Update phpunit, annotate last unreleased changes

Author: samizdam

CHANGELOG.md

@@ -6,6 +6,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Fixed
+- Implicitly marking parameters as nullable is deprecated, the explicit nullable type must be used instead
+
+### Added
+- PHP 8.4 mainline support
+- PHP 8.5 experimental support
+
 ## [4.0.1] - 2024-10-09
 
 ### Fixed

composer.json

@@ -9,7 +9,7 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.3"
+        "phpunit/phpunit": "^9.6"
     },
     "license": "BSD-2-Clause",
     "authors": [