ci: generalize emulated Linux wheel builds

Turn the current ppc64le build into the sole matrix entry in a new
general build job for all emulated Linux builds, to make supporting
additional architectures easier.

Human note: The entirety of the commit message is written manually.

Assisted-by: GPT-5.5

Author: xen0n

.github/workflows/wheels.yml

@@ -97,10 +97,17 @@ jobs:
           name: wheels-${{ matrix.name }}
           path: ./wheelhouse/*.whl
 
-  build_wheels_ppc:
-    name: Wheels for linux-ppc
+  build_wheels_emulated_linux:
+    name: Wheels for ${{ matrix.name }}
     runs-on: ubuntu-24.04
     needs: sdist
+    strategy:
+      fail-fast: true
+      matrix:
+        include:
+        - name: linux-ppc64le
+          qemu_platform: linux/ppc64le
+          cibw_arch: ppc64le
 
     steps:
       - uses: actions/setup-python@v6
@@ -109,7 +116,7 @@ jobs:
 
       - uses: docker/setup-qemu-action@v4
         with:
-          platforms: linux/ppc64le
+          platforms: ${{ matrix.qemu_platform }}
 
       - name: Download sdist
         uses: actions/download-artifact@v8
@@ -124,20 +131,20 @@ jobs:
         shell: bash
         run: python -m cibuildwheel dist/*.tar.gz --output-dir wheelhouse
         env:
-          CIBW_ARCHS: ppc64le
+          CIBW_ARCHS: ${{ matrix.cibw_arch }}
           CIBW_ENVIRONMENT: LIBSSH2_VERSION=1.11.1 LIBGIT2_VERSION=1.9.4 LIBGIT2=/project/ci
 
       - uses: actions/upload-artifact@v7
         with:
-          name: wheels-linux-ppc
+          name: wheels-${{ matrix.name }}
           path: ./wheelhouse/*.whl
 
   twine-check:
     name: Twine check
     # It is good to do this check on non-tagged commits.
     # Note, pypa/gh-action-pypi-publish (see job below) does this automatically.
     if: ${{ !startsWith(github.ref, 'refs/tags/v') }}
-    needs: [build_wheels, build_wheels_ppc, sdist]
+    needs: [build_wheels, build_wheels_emulated_linux, sdist]
     runs-on: ubuntu-latest
 
     steps:
@@ -151,7 +158,7 @@ jobs:
 
   pypi:
     if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
-    needs: [build_wheels, build_wheels_ppc, sdist]
+    needs: [build_wheels, build_wheels_emulated_linux, sdist]
     permissions:
       contents: write # to create GitHub Release
     runs-on: ubuntu-24.04