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]>

.github/workflows/test_docker_debian_codename_sub.yml

@@ -94,7 +94,7 @@ jobs:
 
     # Build base image for debian version name. Layers will be cached and image pushes to local registry
     - name: Build Image - Base
-      uses: docker/build-push-action@v5
+      uses: docker/build-push-action@v6
       with:
         context: .
         load: false
@@ -112,7 +112,7 @@ jobs:
 
     # Build new image with updates packages based on base image. Layers will NOT be chached. Result is written to file.
     - name: Build Image - Update
-      uses: docker/build-push-action@v5
+      uses: docker/build-push-action@v6
       with:
         context: .
         load: false