containerd integration: `docker diff`
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**- What I did**

Implement `docker diff` with containerd store

**- How I did it**

Upstream:
- https://github.com/rumpl/moby/pull/91

**- How to verify it**

(run a container and create a file)
- `docker run -it --name hello alpine`
- `/ # echo world > world.txt && exit`

(verify `diff` works)
- `docker diff hello`

**- Description for the changelog**
<!--
Write a short (one line) summary that describes the changes in this
pull request for inclusion in the changelog:
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**- A picture of a cute animal (not mandatory but encouraged)**

<img width="573" alt="image" src="https://user-images.githubusercontent.com/70572044/217833596-91d46ba3-8469-4dc9-980c-adc6d80cc524.png">


.github/workflows/buildkit.yml
name: buildkit

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

on:
  workflow_dispatch:
  push:
    branches:
      - 'master'
      - '[0-9]+.[0-9]+'
  pull_request:

env:
  DESTDIR: ./build

jobs:
  validate-dco:
    uses: ./.github/workflows/.dco.yml

  build:
    runs-on: ubuntu-20.04
    needs:
      - validate-dco
    steps:
      -
        name: Checkout
        uses: actions/checkout@v3
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2
      -
        name: Build
        uses: docker/bake-action@v2
        with:
          targets: binary
      -
        name: Upload artifacts
        uses: actions/upload-artifact@v3
        with:
          name: binary
          path: ${{ env.DESTDIR }}
          if-no-files-found: error
          retention-days: 1

  test:
    runs-on: ubuntu-20.04
    timeout-minutes: 120
    env:
      BUILDKIT_REPO: moby/buildkit
    needs:
      - build
    strategy:
      fail-fast: false
      matrix:
        worker:
          - dockerd
          - dockerd-containerd
        pkg:
          - client
          - cmd/buildctl
          - solver
          - frontend
          - frontend/dockerfile
        typ:
          - integration
    steps:
      -
        name: Prepare
        run: |
          disabledFeatures="cache_backend_azblob,cache_backend_s3"
          if [ "${{ matrix.worker }}" = "dockerd" ]; then
            disabledFeatures="${disabledFeatures},merge_diff"
          fi
          echo "BUILDKIT_TEST_DISABLE_FEATURES=${disabledFeatures}" >> $GITHUB_ENV
      -
        name: Checkout
        uses: actions/checkout@v3
        with:
          path: moby
      -
        name: BuildKit ref
        run: |
          echo "BUILDKIT_REF=$(./hack/buildkit-ref)" >> $GITHUB_ENV
        working-directory: moby
      -
        name: Checkout BuildKit ${{ env.BUILDKIT_REF }}
        uses: actions/checkout@v3
        with:
          repository: ${{ env.BUILDKIT_REPO }}
          ref: ${{ env.BUILDKIT_REF }}
          path: buildkit
      -
        name: Set up QEMU
        uses: docker/setup-qemu-action@v2
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2
      -
        name: Download binary artifacts
        uses: actions/download-artifact@v3
        with:
          name: binary
          path: ./buildkit/build/moby/
      -
        name: Update daemon.json
        run: |
          sudo rm /etc/docker/daemon.json
          sudo service docker restart
          docker version
          docker info
      -
        name: Test
        run: |
          ./hack/test ${{ matrix.typ }}
        env:
          CONTEXT: "."
          TEST_DOCKERD: "1"
          TEST_DOCKERD_BINARY: "./build/moby/dockerd"
          TESTPKGS: "./${{ matrix.pkg }}"
          TESTFLAGS: "-v --parallel=1 --timeout=30m --run=//worker=${{ matrix.worker }}$"
        working-directory: buildkit

name: buildkit

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

on:
  workflow_dispatch:
  push:
    branches:
      - 'master'
      - '[0-9]+.[0-9]+'
  pull_request:

env:
  DESTDIR: ./build

jobs:
  validate-dco:
    uses: ./.github/workflows/.dco.yml

  build:
    runs-on: ubuntu-20.04
    needs:
      - validate-dco
    steps:
      -
        name: Checkout
        uses: actions/checkout@v3
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2
      -
        name: Build
        uses: docker/bake-action@v2
        with:
          targets: binary
      -
        name: Upload artifacts
        uses: actions/upload-artifact@v3
        with:
          name: binary
          path: ${{ env.DESTDIR }}
          if-no-files-found: error
          retention-days: 1

  test:
    runs-on: ubuntu-20.04
    timeout-minutes: 120
    env:
      BUILDKIT_REPO: moby/buildkit
    needs:
      - build
    strategy:
      fail-fast: false
      matrix:
        worker:
          - dockerd
          - dockerd-containerd
        pkg:
          - client
          - cmd/buildctl
          - solver
          - frontend
          - frontend/dockerfile
        typ:
          - integration
    steps:
      -
        name: Prepare
        run: |
          disabledFeatures="cache_backend_azblob,cache_backend_s3"
          if [ "${{ matrix.worker }}" = "dockerd" ]; then
            disabledFeatures="${disabledFeatures},merge_diff"
          fi
          echo "BUILDKIT_TEST_DISABLE_FEATURES=${disabledFeatures}" >> $GITHUB_ENV
      -
        name: Checkout
        uses: actions/checkout@v3
        with:
          path: moby
      -
        name: BuildKit ref
        run: |
          echo "BUILDKIT_REF=$(./hack/buildkit-ref)" >> $GITHUB_ENV
        working-directory: moby
      -
        name: Checkout BuildKit ${{ env.BUILDKIT_REF }}
        uses: actions/checkout@v3
        with:
          repository: ${{ env.BUILDKIT_REPO }}
          ref: ${{ env.BUILDKIT_REF }}
          path: buildkit
      -
        name: Set up QEMU
        uses: docker/setup-qemu-action@v2
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2
      -
        name: Download binary artifacts
        uses: actions/download-artifact@v3
        with:
          name: binary
          path: ./buildkit/build/moby/
      -
        name: Update daemon.json
        run: |
          sudo rm /etc/docker/daemon.json
          sudo service docker restart
          docker version
          docker info
      -
        name: Test
        run: |
          ./hack/test ${{ matrix.typ }}
        env:
          CONTEXT: "."
          TEST_DOCKERD: "1"
          TEST_DOCKERD_BINARY: "./build/moby/dockerd"
          TESTPKGS: "./${{ matrix.pkg }}"
          # Skip buildkit tests checking the digest (see https://github.com/moby/buildkit/pull/3736)
          TESTFLAGS: "-v --parallel=1 --timeout=30m --run=/^Test([^R]|.[^e]|..[^p]|...[^r]|....[^o]|.....[^S])/worker=${{ matrix.worker }}$"
        working-directory: buildkit

OOF 🙈
Could we also include the test name `TestReproSourceDateEpoch` in the comment? Just to make it easier to understand what is expected to be skipped without having to scan through the linked PR.