Fix AstroidError in similarity checker with imports/signatures igno…

…red (pylint-dev#6357)

Co-authored-by: Daniël van Noord <13665637+DanielNoord@users.noreply.github.com>

pylint/checkers/similar.py

@@ -35,6 +35,7 @@
 from typing import (
     TYPE_CHECKING,
     Any,
+    Callable,
     Dict,
     List,
     NamedTuple,
@@ -375,10 +376,10 @@ def append_stream(
             LineSet(
                 streamid,
                 lines,
-                self.namespace.ignore_comments,
-                self.namespace.ignore_docstrings,
-                self.namespace.ignore_imports,
-                self.namespace.ignore_signatures,
+                self.ignore_comments,
+                self.ignore_docstrings,
+                self.ignore_imports,
+                self.ignore_signatures,
                 line_enabled_callback=self.linter._is_one_message_enabled  # type: ignore[attr-defined]
                 if hasattr(self, "linter")
                 else None,
@@ -559,8 +560,8 @@ def stripped_lines(
     ignore_docstrings: bool,
     ignore_imports: bool,
     ignore_signatures: bool,
-    line_enabled_callback: Callable[[str, int], bool] | None = None,
-) -> list[LineSpecifs]:
+    line_enabled_callback: Union[Callable[[str, int], bool], None] = None,
+) -> List[LineSpecifs]:
     """Return tuples of line/line number/line type with leading/trailing whitespace and any ignored code features removed.
 
     :param lines: a collection of lines
@@ -670,7 +671,7 @@ def __init__(
         ignore_docstrings: bool = False,
         ignore_imports: bool = False,
         ignore_signatures: bool = False,
-        line_enabled_callback: Callable[[str, int], bool] | None = None,
+        line_enabled_callback: Union[Callable[[str, int], bool], None] = None,
     ) -> None:
         self.name = name
         self._real_lines = lines