Merge pyodide_py into python_stdlib.zip. ### Description

Merges pyodide_py.tar into python_stdlib.zip. This reduces the number of network requests during the initialization.

The original intention of splitting pyodide_py.tar from pyodide.asm.data was to give users an option to provide custom files (#2023), which is now available by modifying python_stdlib.zip directly. So I think there is no reason to have both python_stdlib.zip and pyodide_py.tar.

### Checklists

- [x] Add a [CHANGELOG](https://github.com/pyodide/pyodide/blob/main/docs/project/changelog.md) entry
- [x] Add / update tests

package:
  name: libmagic
  version: "5.42"

source:
  url: https://github.com/file/file/archive/refs/tags/FILE5_42.tar.gz
  sha256: d7374d06451154a628831df58e835fa3263825d0ad593df0fb8a911418d27863

  patches:
    - patches/0001-Hardcode-magic.mgc-location.patch

build:
  type: shared_library
  script: |
    autoreconf --install
    # build magic.mgc natively
    ./configure
    make -j ${PYODIDE_JOBS:-3}
    cp magic/magic.mgc dist
    # build libmagic.so
    emconfigure ./configure \
      CFLAGS="${SIDE_MODULE_CFLAGS}"
    cd src
    emmake make -j ${PYODIDE_JOBS:-3} libmagic.la \
      LDFLAGS="-Xcompiler '${SIDE_MODULE_LDFLAGS}'"
    cp .libs/libmagic.so.1.0.0 ${DISTDIR}/libmagic.so

package:
  name: libmagic
  version: "5.42"

source:
  url: https://github.com/file/file/archive/refs/tags/FILE5_42.tar.gz
  sha256: d7374d06451154a628831df58e835fa3263825d0ad593df0fb8a911418d27863

  patches:
    - patches/0001-Hardcode-magic.mgc-location.patch

build:
  type: shared_library
  script: |
    autoreconf --install
    # build magic.mgc natively
    ./configure
    make -j ${PYODIDE_JOBS:-3}
    cp magic/magic.mgc dist
    # build libmagic.so
    emconfigure ./configure \
      CFLAGS="${SIDE_MODULE_CFLAGS}"
    cd src
    emmake make -j ${PYODIDE_JOBS:-3} libmagic.la \
      LDFLAGS="-Xcompiler '${SIDE_MODULE_LDFLAGS}'"
    cp .libs/libmagic.so.1.0.0 ${DISTDIR}/libmagic.so
