Add unit tests for got_url_rewrite() in src/wp-admin/includes/misc.php

[pbearne]

Reference: https://core.trac.wordpress.org/ticket/65135
This PR adds comprehensive unit tests for the got_url_rewrite() function in src/wp-admin/includes/misc.php.
The tests verify detection across different server environments:

• Apache (via got_mod_rewrite)
• Nginx (via $is_nginx global)
• Caddy (via $is_caddy global)
• Overriding via the got_url_rewrite filter.

Trac ticket: https://core.trac.wordpress.org/ticket/65135

Use of AI Tools

AI assistance: Yes
Tool(s): Junie (JetBrains)
Model(s): gemini-3-flash-preview
Used for: Test structure generation, global variable mocking strategy, and dataProvider implementation.

[github-actions]

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[github-actions]

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