Add support for testing imagestream on RHEL9

Signed-off-by: Petr "Stone" Hracek <[email protected]>

Author: phracek

test/test-lib-postgresql.sh

@@ -28,10 +28,6 @@ function test_postgresql_integration() {
 
 # Check the imagestream
 function test_postgresql_imagestream() {
-  case ${OS} in
-    rhel7|centos7|rhel8) ;;
-    *) echo "Imagestream testing not supported for $OS environment." ; return 0 ;;
-  esac
   local tag="-el7"
   if [ "${OS}" == "rhel8" ]; then
     tag="-el8"