ci: add riscv64 manylinux wheels with native RISE runners

Add riscv64 matrix entries (cp39-cp314t) following the s390x pattern,
with native RISE riscv64 runners instead of QEMU emulation.

Based on the work by @justeph in python-cffi#227, with the addition of:
- Native runner support (ubuntu-24.04-riscv) for faster builds
- Skip QEMU setup for riscv64 (not needed on native hardware)

Verified on native riscv64 hardware (BananaPi F3, SpacemiT K1).
Native RISE runners provided by the RISE project.

Signed-off-by: Bruno Verachten <gounthar@gmail.com>

Author: gounthar

.github/workflows/ci.yaml

@@ -139,9 +139,18 @@ jobs:
           - { spec: cp314-manylinux_s390x, arch: s390x, omit: ${{ env.skip_slow_jobs }} }
           - { spec: cp314t-manylinux_s390x, arch: s390x, omit: ${{ env.skip_slow_jobs }} }
 
+          # riscv64 manylinux
+          - { spec: cp39-manylinux_riscv64, arch: riscv64, test_args: '{package}/src/c', omit: ${{ env.skip_slow_jobs }} }
+          - { spec: cp310-manylinux_riscv64, arch: riscv64, test_args: '{package}/src/c', omit: ${{ env.skip_slow_jobs || env.skip_ci_redundant_jobs }} }
+          - { spec: cp311-manylinux_riscv64, arch: riscv64, test_args: '{package}/src/c', omit: ${{ env.skip_slow_jobs || env.skip_ci_redundant_jobs }} }
+          - { spec: cp312-manylinux_riscv64, arch: riscv64, test_args: '{package}/src/c', omit: ${{ env.skip_slow_jobs || env.skip_ci_redundant_jobs }} }
+          - { spec: cp313-manylinux_riscv64, arch: riscv64, test_args: '{package}/src/c', omit: ${{ env.skip_slow_jobs || env.skip_ci_redundant_jobs }} }
+          - { spec: cp314-manylinux_riscv64, arch: riscv64, omit: ${{ env.skip_slow_jobs }} }
+          - { spec: cp314t-manylinux_riscv64, arch: riscv64, omit: ${{ env.skip_slow_jobs }} }
+
   linux:
     needs: [python_sdist, make_linux_matrix]
-    runs-on: ${{ (matrix.arch == 'aarch64') && 'ubuntu-24.04-arm' || 'ubuntu-24.04' }}
+    runs-on: ${{ (matrix.arch == 'aarch64') && 'ubuntu-24.04-arm' || (matrix.arch == 'riscv64') && 'ubuntu-24.04-riscv' || 'ubuntu-24.04' }}
     strategy:
       fail-fast: false
       matrix: ${{ fromJSON(needs.make_linux_matrix.outputs.matrix_json) }}
@@ -155,7 +164,7 @@ jobs:
 
     - name: configure docker foreign arch support
       uses: docker/setup-qemu-action@v3
-      if: matrix.arch != 'x86_64' && matrix.arch != 'i686' && matrix.arch != 'aarch64'
+      if: matrix.arch != 'x86_64' && matrix.arch != 'i686' && matrix.arch != 'aarch64' && matrix.arch != 'riscv64'
 
     - name: build/test wheels
       id: build
@@ -179,6 +188,7 @@ jobs:
         CIBW_MANYLINUX_AARCH64_IMAGE: ${{ matrix.manylinux_img || 'manylinux2014' }}
         CIBW_MANYLINUX_PPC64LE_IMAGE: ${{ matrix.manylinux_img || 'manylinux2014' }}
         CIBW_MANYLINUX_S390X_IMAGE: ${{ matrix.manylinux_img || 'manylinux2014' }}
+        CIBW_MANYLINUX_RISCV64_IMAGE: ${{ matrix.manylinux_img || 'manylinux_2_39' }}
         CIBW_MUSLLINUX_X86_64_IMAGE: ${{ matrix.musllinux_img || 'musllinux_1_2' }}
         CIBW_MUSLLINUX_I686_IMAGE: ${{ matrix.musllinux_img || 'musllinux_1_2' }}
         CIBW_MUSLLINUX_AARCH64_IMAGE: ${{ matrix.musllinux_img || 'musllinux_1_2' }}