fix(ci): upgrade Docker actions to Node.js 24 compatible versions

Node.js 20 is deprecated on GitHub Actions runners starting June 2, 2026.
Upgrade all Docker actions: setup-qemu v3→v4, setup-buildx v3→v4,
login v3→v4, metadata v5→v6, build-push v5→v7.

Author: fmaass

.github/workflows/build-deploy.yml

@@ -73,21 +73,21 @@ jobs:
           path: docs-web/target
 
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
+        uses: docker/setup-qemu-action@v4
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
 
       - name: Log in to GHCR
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Docker metadata
         id: metadata
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           flavor: |
@@ -98,7 +98,7 @@ jobs:
             type=raw,value={{branch}}-rc-{{sha}},enable=${{ startsWith(github.ref, 'refs/heads/release/') }}
 
       - name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v7
         with:
           context: .
           platforms: linux/amd64,linux/arm64