List View: Speed up opening by removing a forced style recalculation

[Mamaduka]

What?

PR replaces the imperative textContent self-assignment in AriaReferencedText with a key on the element, so React replaces the node instead of updating its text in place.

Why?

AriaReferencedText renders once per List View row. Its useEffect set textContent on the node after every commit, invalidating the style for the whole document. Because that write lands between layout reads, the next reader pays for a full style recalculation, twice per open.

Testing Instructions

Same as in #51035.

1. Use Firefox.
2. Create a post and add some blocks (5 paragraphs for instance).
3. Enable List view.
4. Try to navigate and delete a block inside the list view. (Using the options menu for deletion is recommended to ignore a known issue of screen readers sometimes skip announcing the focused element after deleting with keyboard shortcut for now.)
5. Expect the screen readers to announce the correct description for the focused element.

Testing Instructions for Keyboard

Same.

Screenshots or screencast

The last two Perf checks on run CI for listViewOpen metric.

Use of AI Tools

Assisted by Claude.

[github-actions]

Size Change: -29 B (0%)

Total Size: 7.76 MB

📦 View Changed

Filename	Size	Change
build/scripts/block-editor/index.min.js	428 kB	-29 B (-0.01%)

_{compressed-size-action}

[github-actions]

Flaky tests detected in 861514a.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/30528988137
📝 Reported issues:

• [Flaky Test] should update the HTML only for the latest navigation #78835 in /test/e2e/specs/interactivity/router-navigate.spec.ts

[github-actions]

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Co-authored-by: Mamaduka <mamaduka@git.wordpress.org>
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[Mamaduka]

Did a combined run of all three PRs, perf improvement is almost 50% - #80984.

Screenshot

[andrewserong]

Oh clever! Yeah, we're only ever passing a string to this, so this feels like a safe change, and it's testing just as on trunk in Firefox with Voice Over on Mac for me.

[Mamaduka]

Thanks for testing, @andrewserong 🙇