fix: replace JSX.Element with Element in JSDoc return types

The `@wordpress/eslint-plugin` 24.2.0 bump made `jsdoc/no-undefined-types`
stricter, causing lint failures for `{JSX.Element}` return annotations.

This aligns with how Gutenberg handles it — `Element` is included in the
plugin's `definedTypes` via `temporaryWordPressInternalTypes`, while bare
`JSX` is not a recognized type.

Author: dcalhoun

src/components/default-block-appender/index.jsx

@@ -15,7 +15,7 @@ import './style.scss';
  * Renders a hidden button that, when clicked, inserts a new paragraph block
  * at the end of the block editor.
  *
- * @return {JSX.Element} The rendered button element.
+ * @return {Element} The rendered button element.
  */
 export default function DefaultBlockAppender() {
 	const { insertBlock } = useDispatch( blockEditorStore );

src/components/editor-load-error/index.jsx

@@ -17,7 +17,7 @@ import './style.scss';
  * @param {Object} props       Component props
  * @param {string} props.error Error message displayed in the notice
  *
- * @return {JSX.Element} Editor load error component
+ * @return {Element} Editor load error component
  */
 const EditorLoadError = ( { error } ) => {
 	const errorMessage = error.message || error;

src/components/editor-load-notice/index.jsx

@@ -17,7 +17,7 @@ const pluginLoadFailedNotice = __(
  * @param {string}  props.className        Additional class names to apply.
  * @param {boolean} props.pluginLoadFailed Whether plugin loading failed.
  *
- * @return {?JSX.Element} The rendered component or null if no notice is present.
+ * @return {?Element} The rendered component or null if no notice is present.
  */
 export default function EditorLoadNotice( { className, pluginLoadFailed } ) {
 	const { notice, clearNotice } = useEditorLoadNotice(

src/components/editor-toolbar/index.jsx

@@ -36,7 +36,7 @@ import { useScrollIndicators } from './use-scroll-indicators';
  *
  * @param {Object} props           Component props.
  * @param {string} props.className Component classes.
- * @return {JSX.Element} The rendered editor toolbar component.
+ * @return {Element} The rendered editor toolbar component.
  */
 const EditorToolbar = ( { className } ) => {
 	const { enableNativeBlockInserter } = getGBKit();

src/components/editor/index.jsx

@@ -34,7 +34,7 @@ import { usePlusAutocompleter } from './use-plus-autocompleter';
  * @param {boolean}                              props.hideTitle Whether to hide the title input.
  * @param {import('@wordpress/element').Element} props.children  The children to render in the editor.
  *
- * @return {JSX.Element} The rendered App component.
+ * @return {Element} The rendered App component.
  */
 export default function Editor( { post, children, hideTitle } ) {
 	const editorRef = useRef( null );

src/components/layout/index.jsx

@@ -21,7 +21,7 @@ import './style.scss';
  * @param {Object}  props                  The settings passed along to the Editor component.
  * @param {boolean} props.pluginLoadFailed Whether plugin loading failed.
  *
- * @return {JSX.Element} The rendered Layout component.
+ * @return {Element} The rendered Layout component.
  */
 export default function Layout( props ) {
 	const { pluginLoadFailed, ...editorProps } = props;

src/components/text-editor/index.jsx

@@ -14,7 +14,7 @@ import './style.scss';
  * @param {Object}  props           Component props.
  * @param {boolean} props.hideTitle Whether to hide the title input.
  *
- * @return {JSX.Element} The rendered text editor component.
+ * @return {Element} The rendered text editor component.
  */
 export default function TextEditor( { hideTitle } ) {
 	return (

src/components/visual-editor/index.jsx

@@ -52,7 +52,7 @@ const alignCSS = `.is-root-container.alignwide { max-width: var(--wp--style--glo
  * @param {Object}  props           Component props.
  * @param {boolean} props.hideTitle Whether to hide the title input.
  *
- * @return {JSX.Element} The rendered Editor component.
+ * @return {Element} The rendered Editor component.
  */
 function VisualEditor( { hideTitle } ) {
 	const editorPostTitleRef = useRef();