ci: port arm 32-bit job

Co-authored-by: Max Edwards <[email protected]>

Author: willcl-ark

.github/workflows/ci.yml

@@ -453,3 +453,46 @@ jobs:
           path: ${{ env.CCACHE_DIR }}
           # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#update-a-cache
           key: ${{ github.job }}-ccache-${{ github.run_id }}
+
+  ci-matrix:
+    name: ${{ matrix.name }}
+    needs: runners
+    runs-on: ${{ needs.runners.outputs.use-cirrus-runners == 'true' && matrix.cirrus-runner || matrix.fallback-runner }}
+    if: ${{ vars.SKIP_BRANCH_PUSH != 'true' || github.event_name == 'pull_request' }}
+    timeout-minutes: ${{ matrix.timeout-minutes }}
+
+    env:
+      DANGER_CI_ON_HOST_FOLDERS: 1
+      FILE_ENV: ${{ matrix.file-env }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: '32 bit ARM, unit tests, no functional tests'
+            cirrus-runner: 'ubuntu-24.04-arm' # Cirrus' Arm runners are Apple (with virtual Linux aarch64), which doesn't support 32-bit mode
+            fallback-runner: 'ubuntu-24.04-arm'
+            timeout-minutes: 120
+            file-env: './ci/test/00_setup_env_arm.sh'
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+
+      - name: Configure environment
+        uses: ./.github/actions/configure-environment
+
+      - name: Restore caches
+        id: restore-cache
+        uses: ./.github/actions/restore-caches
+
+      - name: Configure Docker
+        uses: ./.github/actions/configure-docker
+        with:
+          use-cirrus: ${{ needs.runners.outputs.use-cirrus-runners }}
+
+      - name: CI script
+        run: ./ci/test_run_all.sh
+
+      - name: Save caches
+        uses: ./.github/actions/save-caches