Bump docker/build-push-action from 3 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 3 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v3...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/rabbit_consumer.yaml

@@ -72,7 +72,7 @@ jobs:
         run: echo "sha_short=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
 
       - name: Build and push to staging project
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v6
         with:
           cache-from: type=gha
           cache-to: type=gha,mode=max
@@ -113,7 +113,7 @@ jobs:
               - 'OpenStack-Rabbit-Consumer/version.txt'
 
       - name: Build and push on version change
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v6
         if: steps.release_updated.outputs.version == 'true'
         with:
           cache-from: type=gha