Use an assertion instead of a type ignore

Author: correctmost

astroid/brain/brain_hypothesis.py

@@ -16,6 +16,8 @@ def a_strategy(draw):
 
     a_strategy()
 """
+from typing import TYPE_CHECKING
+
 from astroid.manager import AstroidManager
 from astroid.nodes.scoped_nodes import FunctionDef
 
@@ -41,7 +43,10 @@ def remove_draw_parameter_from_composite_strategy(node: FunctionDef) -> Function
     first argument (`draw`) - it's always supplied by Hypothesis so we don't
     need to emit the no-value-for-parameter lint.
     """
-    del node.args.args[0]  # type: ignore[union-attr]
+    if TYPE_CHECKING:
+        assert isinstance(node.args.args, list)
+
+    del node.args.args[0]
     del node.args.annotations[0]
     del node.args.type_comment_args[0]
     return node