Remove @shopify/react-testing

[gonzaloriestra]

WHY are these changes introduced?

Fixes #0000

WHAT is this pull request doing?

❯ pnpm install
Scope: all 14 workspace projects
 WARN  7 deprecated subdependencies found: boolean@3.2.0, glob@10.5.0, glob@7.2.3, glob@8.1.0, inflight@1.0.6, node-domexception@1.0.0, whatwg-encoding@3.1.1
Packages: +1
+
Progress: resolved 1977, reused 1827, downloaded 0, added 1, done
Done in 3.6s using pnpm v10.11.1

How to test your changes?

Post-release steps

Measuring impact

How do we know this change was effective? Please choose one:

• n/a - this doesn't need measurement, e.g. a linting rule or a bug-fix
• Existing analytics will cater for this addition
• PR includes analytics changes to measure impact

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes

[gonzaloriestra]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Remove @shopify/react-testing #6920 👈 (View in Graphite)
• Remove @shopify/react-i18n #6919
• Remove some deprecated dependencies #6918
• Fix peer dependencies issues #6898
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	76.94%	14539/18897
🟡	Branches	70.62%	7237/10248
🟡	Functions	75.93%	3694/4865
🟡	Lines	78.45%	13742/17517

Test suite run success

3788 tests passing in 1448 suites.

Report generated by 🧪jest coverage report action from 3d1ef35