Tests: Expand E2E tests for admin screens

[priethor]

What

Part of #315.

Expands E2E Playwright tests for Post Type admin screens.

Why

To test a real, complex worfklow across screens.

How

Adding 2 new tests to create-post-type.spec.ts:

Test	Description
should trash and restore a post type	Verifies bulk trash and untrash actions work correctly
should create hierarchical post type with taxonomy and field group	Integration test creating linked entities and verifying they work together on the actual custom post type

Integration test workflow:

1. Create taxonomy (e2estatus)
2. Create hierarchical post type (e2eproject) linked to taxonomy
3. Verify hierarchical setting persists after save
4. Navigate to custom post type edit screen and verify taxonomy panel appears
5. Create field group with location rule for the custom post type
6. Verify field group metabox appears on custom post type edit screen
7. Verify all entities appear in their respective admin lists
8. Clean up all created entities

Testing Instructions

Run the E2E tests:

npm run test:e2e:playwright -- tests/e2e/create-post-type.spec.ts

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props priethor.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 27.82%. Comparing base (fb6166e) to head (8e9b237).
⚠️ Report is 1 commits behind head on trunk.

Additional details and impacted files

@@             Coverage Diff              @@
##              trunk     #337      +/-   ##
============================================
- Coverage     27.92%   27.82%   -0.10%     
  Complexity     4410     4410              
============================================
  Files           291      291              
  Lines         36916    36916              
============================================
- Hits          10307    10271      -36     
- Misses        26609    26645      +36     

Flag	Coverage Δ
e2e	42.91% <ø> (-0.51%)	⬇️
javascript	6.53% <ø> (ø)
phpunit	24.98% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.