Restore proposed API check (microsoft#183487)

Now that the copilot chat extension is updated and this won't break it

Author: roblourens

src/vs/workbench/api/common/extHost.api.impl.ts

@@ -1292,8 +1292,7 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 				return extHostChat.sendInteractiveRequestToProvider(providerId, message);
 			},
 			get onDidPerformUserAction() {
-				// TODO this needs to be staged with a copilot chat update
-				// checkProposedApiEnabled(extension, 'interactiveUserActions');
+				checkProposedApiEnabled(extension, 'interactiveUserActions');
 				return extHostChat.onDidPerformUserAction;
 			}
 		};