[config] Make the linter optional during config parsing

This will permit to parse config file without having to instantiate
a linter for tool working on pylint configuration like #5462

Author: Pierre-Sassoulas

pylint/config/config_file_parser.py

@@ -26,7 +26,7 @@
 class _ConfigurationFileParser:
     """Class to parse various formats of configuration files."""
 
-    def __init__(self, verbose: bool, linter: PyLinter) -> None:
+    def __init__(self, verbose: bool, linter: PyLinter | None = None) -> None:
         self.verbose_mode = verbose
         self.linter = linter
 
@@ -64,7 +64,8 @@ def _parse_toml_file(self, file_path: Path) -> tuple[dict[str, str], list[str]]:
             with open(file_path, mode="rb") as fp:
                 content = tomllib.load(fp)
         except tomllib.TOMLDecodeError as e:
-            self.linter.add_message("config-parse-error", line=0, args=str(e))
+            if self.linter is not None:
+                self.linter.add_message("config-parse-error", line=0, args=str(e))
             return {}, []
 
         try:
@@ -109,5 +110,6 @@ def parse_config_file(
                 return self._parse_toml_file(file_path)
             return self._parse_ini_file(file_path)
         except (configparser.Error, tomllib.TOMLDecodeError) as e:
-            self.linter.add_message("config-parse-error", line=0, args=str(e))
+            if self.linter is not None:
+                self.linter.add_message("config-parse-error", line=0, args=str(e))
             return {}, []