Problem/Motivation
ContextAwarePluginBase was deprecated in #2273381: Convert ContextAwarePluginBase to traits.
However, only a runtime deprecation was added. The class phpDoc was not updated to include a @deprecated tag. This prevents it from being picked up my PHPStan's deprecation rules or other static analysis tools.
Steps to reproduce
Scan code extending the class using phpstan + phpstan-drupal + phpstan-deprecation-rules (aka drupal-check or upgrade_status). No error about a class extending this base class.
Proposed resolution
Add @deprecated