adding arm linux to os matrix

.github/workflows/build.yml

@@ -34,6 +34,10 @@ jobs:
           - os: "ubuntu-latest"
             cibuild: "*musllinux*"
             cibw_arch: "musllinux"
+          - os: "ubuntu-24.04-arm"  # aarch64 manylinux on ARM runner
+            cibuild: "*manylinux*"
+            cibw_arch: "manylinux"
+
     steps:
       - name: Free Disk Space (Ubuntu)
         if: matrix.os == 'ubuntu-latest'
@@ -90,43 +94,43 @@ jobs:
     name: Make SDist
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+      - uses: actions/checkout@v4
 
-    - name: Build SDist
-      run: pipx run build --sdist
+      - name: Build SDist
+        run: pipx run build --sdist
 
-    - uses: actions/upload-artifact@v4
-      with:
-        name: artifact-sdist
-        path: dist/*.tar.gz
+      - uses: actions/upload-artifact@v4
+        with:
+          name: artifact-sdist
+          path: dist/*.tar.gz
 
   upload_to_test_pypy:
     needs: [build, make_sdist]
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/download-artifact@v4
-      with:
-        merge-multiple: true
-        path: dist
+      - uses: actions/download-artifact@v4
+        with:
+          merge-multiple: true
+          path: dist
 
-    - uses: pypa/gh-action-pypi-publish@v1.12.4
+      - uses: pypa/gh-action-pypi-publish@v1.12.4
       continue-on-error: true   # might fail if we don't bump the version
-      with:
-        user: __token__
-        password: ${{ secrets.test_pypi_password }}
-        repository-url: https://test.pypi.org/legacy/
+        with:
+          user: __token__
+          password: ${{ secrets.test_pypi_password }}
+          repository-url: https://test.pypi.org/legacy/
 
   upload_to_pypi:
     needs: [build, make_sdist]
     runs-on: ubuntu-latest
     if: github.event_name == 'release' && github.event.action == 'published'
     steps:
-    - uses: actions/download-artifact@v4
-      with:
-        merge-multiple: true
-        path: dist
+      - uses: actions/download-artifact@v4
+        with:
+          merge-multiple: true
+          path: dist
 
-    - uses: pypa/gh-action-pypi-publish@v1.12.4
-      with:
-        user: __token__
-        password: ${{ secrets.pypi_password }}
+      - uses: pypa/gh-action-pypi-publish@v1.12.4
+        with:
+          user: __token__
+          password: ${{ secrets.pypi_password }}