Cover RemoveDeadParamFixer for anonymous functions

[TomasVotruba]

The RemoveDeadParamFixer already removes dead @param $value lines (name, no type) from functions and methods. This also applies to anonymous functions — e.g. a docblock above $cleanup = function (...).

Adds a fixture proving the behavior for anonymous functions. No production code change needed — the fixer already handles it.

Example

-/**
- * @param $mappedFields
- * @param $fieldType
- */
 $cleanup = function (array &$mappedFields, string $fieldType) {
 };

• phpstan ✅
• rector ✅
• check-cs ✅
• phpunit (279) ✅