CI: Use public ARM64 Github actions runners for ARM64 builds (#5305)

.github/workflows/ci.yml

@@ -83,14 +83,27 @@ jobs:
         run: crystal build --warnings all --error-on-warnings --error-trace src/invidious.cr
 
   build-docker:
+    strategy:
+      matrix:
+        include:
+          - os: ubuntu-latest
+            name: "AMD64"
+            # GitHub doesn't have a ubuntu-latest-arm runner
+          - os: ubuntu-24.04-arm
+            name: "ARM64"
 
-    runs-on: ubuntu-latest
+    name: Test ${{ matrix.name }} Docker build
+    runs-on: ${{ matrix.os }}
 
     steps:
       - uses: actions/checkout@v5
 
+      - name: Use ARM64 Dockerfile if ARM64
+        if: ${{ matrix.name }} == "ARM64"
+        run: sed -i 's/Dockerfile/Dockerfile.arm64/' docker-compose.yml
+
       - name: Build Docker
-        run: docker compose build --build-arg release=0
+        run: docker compose build
 
       - name: Run Docker
         run: docker compose up -d
@@ -98,32 +111,6 @@ jobs:
       - name: Test Docker
         run: while curl -Isf http://localhost:3000; do sleep 1; done
 
-  build-docker-arm64:
-
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v5
-
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
-        with:
-          platforms: arm64
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-
-      - name: Build Docker ARM64 image
-        uses: docker/build-push-action@v6
-        with:
-          context: .
-          file: docker/Dockerfile.arm64
-          platforms: linux/arm64/v8
-          build-args: release=0
-
-      - name: Test Docker
-        run: while curl -Isf http://localhost:3000; do sleep 1; done
-
   lint:
 
     runs-on: ubuntu-latest