Do not cache configuration files

Fixes PyCQA#1994

isort can run in long processes when used in an editor.  In that
scenario it is confusing for users when editing a configuration file
does not change isorts outcome.

Remove the caches in `settings.py` completely to re-read the
configuration on each run.

This is safe for the CLI case as we here either use the `Trie`
implementation which collects all known configuration files beforehand,
or we exactly construct one `Config` object based on the first filename,
the working dir, or the explicit `settings_path|file` settings.

Not caching is therefore more efficient for the CLI case and more
useful for the editor case.

isort/settings.py

@@ -11,7 +11,6 @@
 import subprocess  # nosec: Needed for gitignore support.
 import sys
 from dataclasses import dataclass, field
-from functools import lru_cache
 from pathlib import Path
 from typing import (
     TYPE_CHECKING,
@@ -766,7 +765,6 @@ def _abspaths(cwd: str, values: Iterable[str]) -> Set[str]:
     return paths
 
 
-@lru_cache()
 def _find_config(path: str) -> Tuple[str, Dict[str, Any]]:
     current_directory = path
     tries = 0
@@ -799,7 +797,6 @@ def _find_config(path: str) -> Tuple[str, Dict[str, Any]]:
     return (path, {})
 
 
-@lru_cache()
 def find_all_configs(path: str) -> Trie:
     """
     Looks for config files in the path provided and in all of its sub-directories.
@@ -828,7 +825,6 @@ def find_all_configs(path: str) -> Trie:
     return trie_root
 
 
-@lru_cache()
 def _get_config_data(file_path: str, sections: Tuple[str]) -> Dict[str, Any]:
     settings: Dict[str, Any] = {}