This fixes a memory leak where using @lru_cache on the is_git_repo() instance
method prevented garbage collection of Repository instances. The cache
dictionary held references to self, keeping instances alive indefinitely.
The fix replaces the @lru_cache decorator with instance-level caching using
a _is_git_repo_cache attribute. This maintains O(1) performance for repeated
calls while allowing proper garbage collection when instances go out of scope.
Fixes#4210
Co-Authored-By: João <joao@crewai.com>
a32a8955ef