Remove redundant @jest-environment jsdom pragma and lint against it

[manzoorwanijk]

What?

Follow up to #77563 (comment)

Removes the @jest-environment jsdom pragma that #77563 reintroduced, and adds an ESLint rule so it does not come back.

Why?

#79672 removed these pragmas repo-wide. jsdom is already the default testEnvironment in @wordpress/jest-preset-default, so the pragma is a no-op, and it breaks under the isolated node_modules layout.

Since nothing prevented it from being added back, a lint rule is needed alongside the removal.

How?

• Deleted the pragma docblock from packages/block-library/src/navigation/test/view.js.
• Added no-warning-comments with @jest-environment jsdom as a banned term to the existing Jest override block in tools/eslint/config.mjs. It is the only core ESLint rule that inspects comment text, so no custom rule is needed. The rule's rules object is re-spread from eslint-plugin-jest's recommended config so the plugin's own rules stay active.

Scoped to **/test/** and **/__tests__/**, excluding e2e/performance/storybook-playwright. @jest-environment node pragmas are genuine overrides and remain untouched.

Testing Instructions

1. npm run lint:js -- packages/block-library/src/navigation/test/view.js passes.
2. Re-add the pragma to any unit test file and confirm ESLint errors with no-warning-comments.
3. Confirm the node overrides still lint clean:

   npm run lint:js -- packages/compose/src/hooks/use-media-query/test/ssr.js packages/vips/src/test packages/theme/src/stylelint-plugins/test
   

4. npm run test:unit -- packages/block-library/src/navigation/test/view.js passes under the default jsdom environment.

Testing Instructions for Keyboard

N/A — test and tooling only, no UI.

Screenshots or screencast

N/A

Use of AI Tools

This pull request was authored with assistance from Claude Code. All changes were reviewed by the contributor.

[github-actions]

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Co-authored-by: manzoorwanijk <manzoorwanijk@git.wordpress.org>
Co-authored-by: aduth <aduth@git.wordpress.org>

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[github-actions]

Size Change: 0 B

Total Size: 7.75 MB

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[github-actions]

Flaky tests detected in fc5c087.
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/30086843667
📝 Reported issues:

• [Flaky Test] should paste block styles using keyboard #78759 in /test/e2e/specs/editor/various/list-view.spec.js

[aduth]

LGTM 👍 Confirmed that the test still passes and that trying to re-add the comment yields a lint error.

[t-hamano]

Since #77563 was backported to 7.1, let's backport this PR as well.

[github-actions]

I just cherry-picked this PR to the wp/7.1 branch to get it included in the next release: d312a5a