ci: add riscv64 wheel builds to release workflow

Add a build_wheels_riscv64 job mirroring the existing arm64 QEMU-based
build. Uses cibuildwheel with QEMU emulation for linux/riscv64, targeting
CPython 3.10-3.14 on manylinux.

Closes #2138

Author: gounthar

.github/workflows/build-and-release.yaml

@@ -85,6 +85,35 @@ jobs:
           name: wheels_arm64
           path: ./wheelhouse/*.whl
 
+  build_wheels_riscv64:
+    name: Build riscv64 wheels
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: "recursive"
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+        with:
+          platforms: linux/riscv64
+
+      - name: Build wheels
+        uses: pypa/cibuildwheel@v2.22.0
+        env:
+          CIBW_SKIP: "*musllinux* pp*"
+          CIBW_REPAIR_WHEEL_COMMAND: ""
+          CIBW_ARCHS: "riscv64"
+          CIBW_BUILD: "cp310-* cp311-* cp312-* cp313-* cp314-*"
+        with:
+          output-dir: wheelhouse
+
+      - name: Upload wheels as artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: wheels_riscv64
+          path: ./wheelhouse/*.whl
+
   build_sdist:
     name: Build source distribution
     runs-on: ubuntu-latest
@@ -129,7 +158,7 @@ jobs:
 
   release:
     name: Release
-    needs: [build_wheels, build_wheels_arm64, build_sdist]
+    needs: [build_wheels, build_wheels_arm64, build_wheels_riscv64, build_sdist]
     runs-on: ubuntu-latest
 
     steps: