isFrontPage() returns a stale result after the current route changes

Problem/Motivation

Drupal's PathMatcher::isFrontPage() and the AliasPathMatcher decorator each cache their result in an isCurrentFrontPage property. Neither property is reset between requests.

When FrankenPHP worker mode reuses the kernel and services, subsequent requests receive the cached result from the first request. A cached TRUE incorrectly identifies other routes as the front page. A cached FALSE prevents later front-page requests from matching.

Steps to reproduce

1. Start a fresh FrankenPHP worker.
2. Request the front page. Front-page detection is cached to TRUE.
3. Request /session/token through the same worker.
4. You get redirected to the front page.

Proposed resolution

Remove the $isCurrentFrontPage property from both classes and compute the result on each call.

If the caching needs to be kept, let's try to find a way to do it that won't go stale for new requests.

AI disclosure: I used AI to help prepare the IS and MR (Astra and Opus 5.5).