Bump docker/build-push-action from 5 to 6 (#24)

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/create-and-test-docker-image.yml

@@ -45,7 +45,7 @@ jobs:
           password: ${{ secrets.DOCKER_PASSWORD }}
 
       - name: Build ${{ inputs.image-tag }}
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: ${{ inputs.source-directory }}
           tags: ${{ inputs.image-tag }}
@@ -60,7 +60,7 @@ jobs:
           run: php /work/test_connection.php
 
       - name: Push ${{ inputs.image-tag }}
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         if: ${{ github.event_name != 'pull_request' }}
         with:
           context: ${{ inputs.source-directory }}