Update Emscripten binary wheels to include Emscripten platform tags. More work split off from #2591.

### Checklists

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


package:
  name: libyaml
  version: 0.2.1

source:
  url: https://github.com/yaml/libyaml/archive/0.2.1.zip
  sha256: 56070c9d4bf244a8dcc68e04613e5bbce5c8411ed97cdccc1f4b5fb46aebe5a8

build:
  library: true
  script: |
    export INSTALL_DIR=${WASM_LIBRARY_DIR}

    CFLAGS="-fPIC" emcmake cmake -DCMAKE_INSTALL_PREFIX=${INSTALL_DIR} .
    emmake make -j ${PYODIDE_JOBS:-3}
    emmake make install
    ln -s libyaml_static.a ${INSTALL_DIR}/lib/libyaml.a

package:
  name: libyaml
  version: 0.2.1

source:
  url: https://github.com/yaml/libyaml/archive/0.2.1.zip
  sha256: 56070c9d4bf244a8dcc68e04613e5bbce5c8411ed97cdccc1f4b5fb46aebe5a8

build:
  library: true
  script: |
    export INSTALL_DIR=${WASM_LIBRARY_DIR}

    CFLAGS="-fPIC" emcmake cmake -DCMAKE_INSTALL_PREFIX=${INSTALL_DIR} .
    emmake make -j ${PYODIDE_JOBS:-3}
    emmake make install
    ln -s libyaml_static.a ${INSTALL_DIR}/lib/libyaml.a
