Move request utils reset to global setup

[swissspidy]

What?

Moves the "reset" logic from the request utils setup to global setup, wehre it belongs.

Fixes #50741
Fixes #52339

Why?

Right now the request utils in e2e-test-utils-playwright contain a lot of Gutenberg-specific logic that does not apply to other setups.

That means everyone trying to use the utils gets errors about things like the gutenberg-test-plugin-disables-the-css-animations plugin or the twentytwentyone theme not existing.

This logic is an ideal candidate for global setup in Playwright.

How?

Testing Instructions

tests should pass

Testing Instructions for Keyboard

Screenshots or screencast

[github-actions]

Flaky tests detected in 42cefe4.
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/5485130687
📝 Reported issues:

• [Flaky Test] should toggle "lightbox" in saved attributes #52350 in /test/e2e/specs/editor/blocks/image.spec.js

[Mamaduka]

Thank you, @swissspidy!