Remove publish-rhel.sh duplication (#205)

The `publish-rhel` script exists in both
[management-center-docker](https://github.com/hazelcast/management-center-docker/blob/7ee26e395fdc7559664787ad08ca08a7091b2650/.github/scripts/publish-rhel.sh)
and
[hazelcast-docker](https://github.com/hazelcast/hazelcast-docker/blob/62e3305bdd4babc8c58556f209edac2933e3fce7/.github/scripts/publish-rhel.sh).

We should use the same script for both.

Note the implementations [aren't exactly the
same](https://www.diffchecker.com/mQDzS91V), but I don't see any
_significant_ divergence - and as `hazelcast-docker`'s is more actively
developer and seems to work ok I think it's ok to use that.

.github/workflows/tag_image_push_rhel.yml

@@ -23,6 +23,12 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Checkout hazelcast-docker repo
+        uses: actions/checkout@v4
+        with:
+          repository: hazelcast/hazelcast-docker
+          path: 'hazelcast-docker'
+
       - name: Set release version as environment variable
         run: |
           echo "RELEASE_VERSION=${GITHUB_REF:11}" >> $GITHUB_ENV
@@ -82,12 +88,14 @@ jobs:
           --submit
 
       - name: Wait for scan to complete
+        working-directory: hazelcast-docker
         run: |
           source .github/scripts/publish-rhel.sh
           
           wait_for_container_scan "${{ env.RHEL_PROJECT_ID }}" "${{ env.RELEASE_VERSION }}" "${{ secrets.RHEL_API_KEY }}" "${{ env.TIMEOUT_IN_MINS }}"
 
       - name: Publish the Management Center image
+        working-directory: hazelcast-docker
         run: |
           source .github/scripts/publish-rhel.sh