Bump docker/build-push-action from 5 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 5 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v5...v6)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -60,7 +60,7 @@ jobs:
       - uses: docker/setup-buildx-action@v3
         name: Set up Docker Buildx
 
-      - uses: docker/build-push-action@v5
+      - uses: docker/build-push-action@v6
         with:
           push: false
           tags: pg-meta:test

.github/workflows/release.yml

@@ -82,7 +82,7 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - uses: docker/build-push-action@v5
+      - uses: docker/build-push-action@v6
         with:
           push: true
           platforms: linux/amd64,linux/arm64