Address a potential memory leak when storing hooks instances (#66)

From Ruff:

> Using the functools.lru_cache and functools.cache decorators on methods can lead to memory leaks, as the global cache will retain a reference to the instance, preventing it from being garbage collected.

Author: oprypin

properdocs/config/config_options.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import functools
+import importlib.util
 import ipaddress
 import logging
 import os
@@ -1172,6 +1173,7 @@ def __init__(self, plugins_key: str) -> None:
         super().__init__()
         self.default = []
         self.plugins_key = plugins_key
+        self._loaded_hooks: dict[tuple[str, str], types.ModuleType] = {}
 
     def pre_validation(self, config: Config, key_name: str):
         self._base_option = ListOfItems(File(exists=True))
@@ -1183,13 +1185,13 @@ def run_validation(self, value: object) -> Mapping[str, Any]:
         assert isinstance(value, list)
 
         hooks = {}
-        for name, path in zip(value, paths):
+        for name, path in zip(value, paths, strict=True):
             hooks[name] = self._load_hook(name, path)
         return hooks
 
-    @functools.cache
-    def _load_hook(self, name, path):
-        import importlib.util
+    def _load_hook(self, name: str, path: str) -> types.ModuleType:
+        if loaded_hook := self._loaded_hooks.get((name, path)):
+            return loaded_hook
 
         spec = importlib.util.spec_from_file_location(name, path)
         if spec is None:
@@ -1206,6 +1208,7 @@ def _load_hook(self, name, path):
         finally:
             sys.path[:] = old_sys_path
 
+        self._loaded_hooks[name, path] = module
         return module
 
     def post_validation(self, config: Config, key_name: str):

pyproject.toml

@@ -180,7 +180,7 @@ select = [
     "F", "E", "W", "I", "UP", "YTT", "ASYNC", "C4", "DTZ", "T10", "FA", "ISC", "PIE", "T20", "RSE",
     "N803", "N804", "N805", "N806", "N807", "N815", "N999",
     "S201", "S202", "S303", "S304", "S305", "S306", "S602", "S604", "S605", "S612",
-    "B002", "B003", "B004", "B005", "B008", "B009", "B010", "B011", "B012", "B013", "B014", "B015", "B016", "B017", "B018", "B020", "B021", "B022", "B023", "B025", "B026", "B029", "B030", "B031", "B032", "B033", "B034", "B035", "B039", "B909",
+    "B002", "B003", "B004", "B005", "B008", "B009", "B010", "B011", "B012", "B013", "B014", "B015", "B016", "B017", "B018", "B019", "B020", "B021", "B022", "B023", "B025", "B026", "B029", "B030", "B031", "B032", "B033", "B034", "B035", "B039", "B909",
     "COM818",
     "D200", "D201", "D202", "D204", "D207", "D208", "D209", "D210", "D211", "D213", "D214", "D300", "D301", "D400", "D402", "D403", "D405", "D412", "D414", "D415", "D416", "D417", "D419",
     "LOG001", "LOG007", "LOG009", "LOG015",