[CI] Do not upload RPM artifacts for CentOS 7

The action to upload-artifact@v3 no longer works due to its
reliance on node16, which has just hit EOL and been removed.
Since upload-artifact@v4 also doesn't work on CentOS 7, the
only option to keep builds running is to not upload results.

https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/

.github/workflows/RPM.yml

@@ -69,16 +69,6 @@ jobs:
     - name: Run post-install tests
       run: tests/post-install.sh
 
-    - name: Move RPMs to Artifact Directory
-      run: mkdir RPMS && mv $(rpm -E '%{_rpmdir}')/*/*.rpm RPMS/
-
-    - name: Upload Artifacts
-      uses: actions/upload-artifact@v3
-      with:
-        name: centos7
-        path: RPMS
-        retention-days: 14
-
   alma8:
     name: Alma Linux 8
     runs-on: ubuntu-latest