build(deps): bump docker/build-push-action from 2 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 2 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v2...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/release_standalone.yaml

@@ -24,7 +24,7 @@ jobs:
           password: ${{ secrets.TOKEN }}
 
       - name: Build and push Docker image
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v6
         with:
           file: ./GridboxConnectorAddon-edge/Dockerfile.standalone
           push: true