[core] Fix rsc build step in CI (#38019)

Author: mj12albert

.circleci/config.yml

@@ -224,7 +224,10 @@ jobs:
           name: '`yarn proptypes` changes committed?'
           command: git diff --exit-code
       - run:
-          name: '`yarn rsc:build` changes committed?'
+          name: 'Write "use client" directive'
+          command: yarn rsc:build
+      - run:
+          name: '`yarn rsc:build` changes detected, "use client" missing from exports'
           command: git diff --exit-code
       - run:
           name: Generate the documentation

packages/mui-joy/src/Skeleton/Skeleton.tsx

@@ -1,3 +1,4 @@
+'use client';
 import * as React from 'react';
 import clsx from 'clsx';
 import PropTypes from 'prop-types';

packages/mui-joy/src/Skeleton/index.ts

@@ -1,3 +1,4 @@
+'use client';
 export { default } from './Skeleton';
 export * from './skeletonClasses';
 export { default as skeletonClasses } from './skeletonClasses';

packages/mui-joy/src/ToggleButtonGroup/ToggleButtonGroup.tsx

@@ -1,3 +1,4 @@
+'use client';
 import * as React from 'react';
 import clsx from 'clsx';
 import PropTypes from 'prop-types';

packages/mui-joy/src/ToggleButtonGroup/index.ts

@@ -1,3 +1,4 @@
+'use client';
 export { default } from './ToggleButtonGroup';
 export * from './toggleButtonGroupClasses';
 export { default as toggleButtonGroupClasses } from './toggleButtonGroupClasses';