Bump docker/build-push-action from 5 to 6 (#256)

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] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/publish.yaml

@@ -35,7 +35,7 @@ jobs:
           password: ${{ secrets.QUAY_PASSWORD }}
       - name: Build and push ${{github.event.release.tag_name }}
         id: docker_build_release
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         if: ${{ github.event.release.tag_name != '' }}
         with:
           push: true
@@ -48,7 +48,7 @@ jobs:
 
       - name: Build and push main
         id: docker_build_main
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         if: ${{ github.event.release.tag_name == '' }}
         with:
           push: true