Remove policy class caching
This removes policy class caching.
This caching was a defensive measure to mitigate against a ruby bug (https://bugs.ruby-lang.org/issues/11119). This was fixed two years ago, and tests confirm that the test suite is no slower with it removed (0.045 sec now vs 0.050 sec before).
See: https://gitlab.com/gitlab-org/declarative-policy/-/issues/4
Edited by Alex Kalderimis