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] <[email protected]>

Author: dependabot[bot]

.github/workflows/build-test-publish.yml

@@ -54,7 +54,7 @@ jobs:
         username: ${{ secrets.DOCKERHUB_USERNAME }}
         password: ${{ secrets.DOCKERHUB_TOKEN }}
     - name: Build and push
-      uses: docker/build-push-action@v5
+      uses: docker/build-push-action@v6
       with:
         context: .
         platforms: linux/amd64, linux/arm64, linux/ppc64le, linux/s390x
@@ -75,7 +75,7 @@ jobs:
           type=sha,suffix=-amd64,latest=false
     - name: Build and push single-arch amd64 image
       if: github.event_name != 'pull_request'
-      uses: docker/build-push-action@v5
+      uses: docker/build-push-action@v6
       with:
         context: .
         platforms: linux/amd64
@@ -97,7 +97,7 @@ jobs:
     - name: Build and push single-arch arm64 image
       if: github.event_name != 'pull_request'
       #if: startsWith(github.ref, 'refs/tags/v')
-      uses: docker/build-push-action@v5
+      uses: docker/build-push-action@v6
       with:
         context: .
         platforms: linux/arm64