ci: fix issues with OSMesa installation and env variables set up

.github/workflows/ci_cd.yml

@@ -203,9 +203,12 @@ jobs:
 
       - name: Set up headless display
         if: env.SKIP_UNSTABLE == 'false'
-        uses: pyvista/setup-headless-display-action@52bda06d59c0fc422fc2512c9c670bf6b66616f8 # v3.2
+        uses: RobPasMue/setup-headless-display-action@offscreen-mesa3d
         with:
           pyvista: false
+          # Mesa3D off screen rendering only needed on Windows self-hosted runners
+          # without GPU support (e.g. pygeometry-ci-2 has GPU, so it doesn't need it)
+          install-mesa3d-offscreen: ${{ runner.name != 'pygeometry-ci-2' }}
 
       - name: Create Python venv
         if: env.SKIP_UNSTABLE == 'false'
@@ -682,6 +685,14 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
+      - name: Set up headless display
+        uses: RobPasMue/setup-headless-display-action@offscreen-mesa3d
+        with:
+          pyvista: false
+          # Mesa3D off screen rendering only needed on Windows self-hosted runners
+          # without GPU support (e.g. pygeometry-ci-2 has GPU, so it doesn't need it)
+          install-mesa3d-offscreen: ${{ runner.name != 'pygeometry-ci-2' }}
+
       - name: Set up Python
         uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
         with:

.github/workflows/nightly_docker_test.yml

@@ -100,9 +100,12 @@ jobs:
           python-version: ${{ env.MAIN_PYTHON_VERSION }}
 
       - name: Set up headless display
-        uses: pyvista/setup-headless-display-action@52bda06d59c0fc422fc2512c9c670bf6b66616f8 # v3.2
+        uses: RobPasMue/setup-headless-display-action@offscreen-mesa3d
         with:
           pyvista: false
+          # Mesa3D off screen rendering only needed on Windows self-hosted runners
+          # without GPU support (e.g. pygeometry-ci-2 has GPU, so it doesn't need it)
+          install-mesa3d-offscreen: ${{ runner.name != 'pygeometry-ci-2' }}
 
       - name: Create Python venv
         run: |

doc/changelog.d/1927.maintenance.md

@@ -0,0 +1 @@
+fix issues with OSMesa installation and env variables set up