[mdalikadar]

Description
Filters::discoverFilters() ran FileLocator::getClassname() on every Config/Filters.php it found, which reads and tokenizes the file, and then skipped the app and system ones because their class is Config\Filters or CodeIgniter\Config\Filters. In a default app those are the only two files, so every request parsed two files it never used.

The two paths are now skipped before getClassname() is called. Every other file keeps the existing class-name check. The paths are built with DIRECTORY_SEPARATOR, as search() returns realpath() results.

On my machine new Filters() with discovery on goes from about 134 µs to about 60 µs (PHP 8.5 CLI, so indicative). It mostly helps apps without FileLocatorCached.

Edge case: an app/Config/Filters.php that declares a class other than Config\Filters used to be included by discovery and is now skipped. That breaks the framework's conventions, and discovery has been deprecated since 4.4.2.

Fixes #10616

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value (without duplication)
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide