Panel: Re-add aria-expanded (accidentally removed)

[ItsJonQ]

This update re-adds the aria-expanded prop to the trigger button within PanelBody. It was accidentally removed in this update. Thanks to @afercia for catching it.

For context, the accidental remove came from an attempt to use Reakit Disclosure. Disclosure handily adds and coordinates various aria attributes for us. Unfortunately, we weren't able to add it at this time. When we reverted the integration, we missed re-adding aria-expanded (which was previously there).

This PR resolves this issue:
#24036

How has this been tested?

• Run npm run dev
• Enable Mac OS Voiceover
• Expand/collapse panels in sidebar
• Ensure the voiceover announces expand/collapse

Checklist:

• My code is tested.
• [n/a] My code follows the WordPress code style.
• My code follows the accessibility standards.
• [n/a] My code has proper inline documentation.
• [n/a] I've included developer documentation if appropriate.
• [n/a] I've updated all React Native files affected by any refactorings/renamings in this PR.

[github-actions]

Size Change: -27 B (0%)

Total Size: 1.15 MB

Filename	Size	Change
build/block-editor/index.min.js	125 kB	-72 B (0%)
build/block-editor/style.css	10.8 kB	+2 B (0%)
build/components/index.min.js	200 kB	+5 B (0%)
build/compose/index.min.js	9.68 kB	+12 B (0%)
build/edit-widgets/index.min.js	9.37 kB	+26 B (0%)

ℹ️ View Unchanged

Filename	Size	Change
build/a11y/index.min.js	1.14 kB	0 B
build/annotations/index.min.js	3.67 kB	0 B
build/api-fetch/index.min.js	3.43 kB	0 B
build/autop/index.min.js	2.82 kB	0 B
build/blob/index.min.js	620 B	0 B
build/block-directory/index.min.js	7.63 kB	0 B
build/block-directory/style-rtl.css	944 B	0 B
build/block-directory/style.css	945 B	0 B
build/block-editor/style-rtl.css	10.8 kB	0 B
build/block-library/editor-rtl.css	7.58 kB	0 B
build/block-library/editor.css	7.57 kB	0 B
build/block-library/index.min.js	132 kB	0 B
build/block-library/style-rtl.css	7.77 kB	0 B
build/block-library/style.css	7.77 kB	0 B
build/block-library/theme-rtl.css	728 B	0 B
build/block-library/theme.css	729 B	0 B
build/block-serialization-default-parser/index.min.js	1.88 kB	0 B
build/block-serialization-spec-parser/index.min.js	3.1 kB	0 B
build/blocks/index.min.js	48.3 kB	0 B
build/components/style-rtl.css	15.6 kB	0 B
build/components/style.css	15.6 kB	0 B
build/core-data/index.min.js	11.5 kB	0 B
build/data-controls/index.min.js	1.29 kB	0 B
build/data/index.min.js	8.45 kB	0 B
build/date/index.min.js	5.38 kB	0 B
build/deprecated/index.min.js	772 B	0 B
build/dom-ready/index.min.js	568 B	0 B
build/dom/index.min.js	3.23 kB	0 B
build/edit-navigation/index.min.js	10.8 kB	0 B
build/edit-navigation/style-rtl.css	1.08 kB	0 B
build/edit-navigation/style.css	1.08 kB	0 B
build/edit-post/index.min.js	304 kB	0 B
build/edit-post/style-rtl.css	5.61 kB	0 B
build/edit-post/style.css	5.61 kB	0 B
build/edit-site/index.min.js	16.8 kB	0 B
build/edit-site/style-rtl.css	3.06 kB	0 B
build/edit-site/style.css	3.06 kB	0 B
build/edit-widgets/style-rtl.css	2.45 kB	0 B
build/edit-widgets/style.css	2.45 kB	0 B
build/editor/editor-styles-rtl.css	537 B	0 B
build/editor/editor-styles.css	539 B	0 B
build/editor/index.min.js	45.3 kB	0 B
build/editor/style-rtl.css	3.78 kB	0 B
build/editor/style.css	3.78 kB	0 B
build/element/index.min.js	4.65 kB	0 B
build/escape-html/index.min.js	733 B	0 B
build/format-library/index.min.js	7.72 kB	0 B
build/format-library/style-rtl.css	547 B	0 B
build/format-library/style.css	548 B	0 B
build/hooks/index.min.js	2.13 kB	0 B
build/html-entities/index.min.js	621 B	0 B
build/i18n/index.min.js	3.56 kB	0 B
build/is-shallow-equal/index.min.js	711 B	0 B
build/keyboard-shortcuts/index.min.js	2.51 kB	0 B
build/keycodes/index.min.js	1.94 kB	0 B
build/list-reusable-blocks/index.min.js	3.12 kB	0 B
build/list-reusable-blocks/style-rtl.css	476 B	0 B
build/list-reusable-blocks/style.css	476 B	0 B
build/media-utils/index.min.js	5.32 kB	0 B
build/notices/index.min.js	1.79 kB	0 B
build/nux/index.min.js	3.4 kB	0 B
build/nux/style-rtl.css	671 B	0 B
build/nux/style.css	668 B	0 B
build/plugins/index.min.js	2.56 kB	0 B
build/primitives/index.min.js	1.4 kB	0 B
build/priority-queue/index.min.js	789 B	0 B
build/redux-routine/index.min.js	2.85 kB	0 B
build/rich-text/index.min.js	13.9 kB	0 B
build/server-side-render/index.min.js	2.71 kB	0 B
build/shortcode/index.min.js	1.7 kB	0 B
build/token-list/index.min.js	1.27 kB	0 B
build/url/index.min.js	4.06 kB	0 B
build/viewport/index.min.js	1.85 kB	0 B
build/warning/index.min.js	1.14 kB	0 B
build/wordcount/index.min.js	1.17 kB	0 B

_{compressed-size-action}

[youknowriad]

Is this the same as #24046 ?

[ItsJonQ]

@youknowriad Oh! I didn't know about that one. Yes, let's go with @diegohaz 's PR. I'll close this one.

Thanks all! ✌️