[Misc] GroupEditPage.removeMembers is flickering

xwiki-platform-core/xwiki-platform-administration/xwiki-platform-administration-test/xwiki-platform-administration-test-pageobjects/src/main/java/org/xwiki/administration/test/po/GroupEditPage.java

@@ -95,6 +95,8 @@ public GroupEditPage removeMembers(String... members)
             for (WebElement row : getMembersTable().getRows()) {
                 if (Objects.equals(getRowUserName(row), member)) {
                     getMembersTable().clickAction(index, "delete");
+                    // Wait for the confirmation message before moving to the next member.
+                    waitForNotificationSuccessMessage("Member successfully removed from group");
                     break;
                 }
                 index++;