### Problem/Motivation Register UseSpecificWillMethodRector to rewrite deprecated PHPUnit mock stub spellings (->will($this->returnValue(...)) to ->willReturn(...)). Enable ExplicitNullableParamTypeRector (php84) to handle ~1784 implicit-nullable parameter cases (Foo $x = null to ?Foo $x = null), and RemoveReflectionSetAccessibleCallsRector (php81) to drop ~865 no-op setAccessible() calls. Wire RenameCast and RemoveFuncCallRector (php85) to handle cast renames and no-op function cleanup. Raise phpVersion to 8.4 to unblock the php84 rules. ### Work items - Commit(s): [d2777cc6ad](https://git.drupalcode.org/project/project_analysis/-/commit/d2777cc6ada9), [840b8aa9f1](https://git.drupalcode.org/project/project_analysis/-/commit/840b8aa9f111), [79793da304](https://git.drupalcode.org/project/project_analysis/-/commit/79793da30418) ### Credit - Implemented by: @bbrala - Test-project feedback: @goba, @nicxvan, @wimleers, @rfay, @larowlan --- *Filed retroactively as part of the Drupal 12 rector coverage effort. Closed as fixed; credit to be applied to the contributors listed above.* *AI was used extensively to build this work and to file this issue. See [Dries Buytaert: AI-generated Rector rules for Drupal](https://dri.es/ai-generated-rector-rules-for-drupal) and [Björn Brala: Drupal Rector rules are config, not code. Mostly.](https://www.linkedin.com/pulse/drupal-rector-rules-config-code-mostly-bj%C3%B6rn-brala-vfpwe/).*