fix: correct wait end of process

Signed-off-by: Philippe Martin <phmartin@redhat.com>

Author: feloy

.github/workflows/e2e-tests.yaml

@@ -192,7 +192,9 @@ jobs:
         run: |
           kill $ENVTEST_START_PID
           # give some time for the cluster to be stopped gracefully
-          sleep 3
+          echo 'waiting process to be stopped...'
+          timeout 10s bash -c 'while ps $ENVTEST_START_PID; do sleep 1; done'
+          echo 'process stopped'
 
       - uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
         if: always()