Add a build for release tar file

.github/workflows/build-base-dev-images.yml

@@ -1,6 +1,8 @@
 name: Build base-dev Images
 
 on:
+    release:
+        types: [published]
     workflow_dispatch:
         inputs:
             tag:

.github/workflows/build-release-tar.yml

@@ -0,0 +1,41 @@
+name: Build Release Tar
+
+on:
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'Tag of the Docker image (e.g. on-water-8)'
+        required: true
+        type: string
+
+jobs:
+  build-tar:
+    runs-on: ubuntu-24.04-arm
+    timeout-minutes: 45
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build image and save to tar
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: .devcontainer/release/release.Dockerfile
+          platforms: linux/arm64
+          build-args: |
+            CACHEBUST=${{ github.run_id }}
+          tags: release:${{ inputs.tag }}
+          push: false
+          outputs: type=docker,dest=release.tar # write the image as a tar
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      - name: Upload tar as artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: release-${{ inputs.tag }}-tar
+          path: release.tar
+          retention-days: 7