PHPUnit 13.3.6 changes

The 29 September release notes describe fixes to retry-attempt reporting and RequiresMethod handling. In particular, a reference to a class that cannot be loaded should skip the relevant test instead of aborting the run.

Check the tagged release notes and the project's compatibility documentation before upgrading. This observation concerns the 13.3.6 release; it does not imply all PHP projects can run that major version.

Related: package signals, type declarations.