ci(devcontainer): Build the workspace once in advance

.github/workflows/ci.yml

@@ -11,12 +11,15 @@ jobs:
     uses: ./.github/workflows/ci_format_code.yml
   build_dev_container:
     uses: ./.github/workflows/ci_build_dev_container.yml
-  build:
+  launch_dev_container:
     needs: build_dev_container
+    uses: ./.github/workflows/ci_launch_dev_container.yml
+  build:
+    needs: launch_dev_container
     uses: ./.github/workflows/ci_build.yml
   test:
-    needs: build_dev_container
+    needs: launch_dev_container
     uses: ./.github/workflows/ci_test.yml
   lint:
-    needs: build_dev_container
+    needs: launch_dev_container
     uses: ./.github/workflows/ci_lint.yml

.github/workflows/ci_launch_dev_container.yml

@@ -0,0 +1,21 @@
+name: CI launch dev container
+'on':
+  workflow_call: null
+jobs:
+  build_dev_container:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout (GitHub)
+        uses: actions/checkout@v4
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Pre-build workspace by executing the container entrypoint
+        uses: devcontainers/[email protected]
+        with:
+          cacheFrom: ghcr.io/vorausrobotik/voraus-ros-bridge-dev
+          runCmd: echo entrypoint execution finished
+          push: never