chore(deps): update docker/metadata-action action to v6

Author: renovate[bot]

.github/workflows/release-please.yaml

@@ -42,7 +42,7 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
       - name: Docker meta
         id: meta
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           images: ghcr.io/${{ github.repository }}
           tags: |
@@ -87,7 +87,7 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
       - name: Docker meta
         id: meta
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           images: ghcr.io/${{ github.repository }}
           tags: |