[Backport maintenance/2.17.x] Clear LRU caches on pylint utilities

doc/whatsnew/fragments/8361.bugfix

@@ -0,0 +1,4 @@
+``--clear-cache-post-run`` now also clears LRU caches for pylint utilities
+holding references to AST nodes.
+
+Closes #8361

pylint/checkers/utils.py

@@ -17,7 +17,7 @@
 from collections.abc import Iterable, Iterator
 from functools import lru_cache, partial
 from re import Match
-from typing import TYPE_CHECKING, Callable, TypeVar
+from typing import TYPE_CHECKING, Any, Callable, TypeVar
 
 import _string
 import astroid.objects
@@ -28,6 +28,8 @@
 from astroid.typing import InferenceResult, SuccessfulInferenceResult
 
 if TYPE_CHECKING:
+    from functools import _lru_cache_wrapper
+
     from pylint.checkers import BaseChecker
 
 _NodeT = TypeVar("_NodeT", bound=nodes.NodeNG)
@@ -2295,3 +2297,20 @@ def not_condition_as_string(
         )
         msg = f"{lhs} {get_inverse_comparator(ops)} {rhs}"
     return msg
+
+
+def clear_lru_caches() -> None:
+    """Clear caches holding references to AST nodes."""
+    # pylint: disable-next=import-outside-toplevel
+    from pylint.checkers.variables import overridden_method
+
+    caches_holding_node_references: list[_lru_cache_wrapper[Any]] = [
+        in_for_else_branch,
+        infer_all,
+        is_overload_stub,
+        overridden_method,
+        unimplemented_abstract_methods,
+        safe_infer,
+    ]
+    for lru in caches_holding_node_references:
+        lru.cache_clear()

pylint/lint/run.py

@@ -12,6 +12,7 @@
 from typing import Any, ClassVar
 
 from pylint import config
+from pylint.checkers.utils import clear_lru_caches
 from pylint.config._pylint_config import (
     _handle_pylint_config_commands,
     _register_generate_config_options,
@@ -222,6 +223,7 @@ def __init__(
             exit = do_exit
 
         if linter.config.clear_cache_post_run:
+            clear_lru_caches()
             MANAGER.clear_cache()
 
         if exit: