types(aafig) Fix typing issues in mypy 1.16.0

Run uv run mypy .
docs/_ext/aafig.py:71: error: Unused "type: ignore" comment  [unused-ignore]
docs/_ext/aafig.py:85: error: Item "None" of "Optional[dict[str, Callable[[str], Any]]]" has no attribute "copy"  [union-attr]
docs/_ext/aafig.py:106: error: "Node" has no attribute "aafig"  [attr-defined]
Found 3 errors in 1 file (checked 99 source files)

Author: tony

docs/_ext/aafig.py

@@ -68,7 +68,7 @@ class AafigError(SphinxError):
     category = "aafig error"
 
 
-class AafigDirective(images.Image):  # type:ignore
+class AafigDirective(images.Image):
     """Directive to insert an ASCII art figure to be rendered by aafigure."""
 
     has_content = True
@@ -82,7 +82,7 @@ class AafigDirective(images.Image):  # type:ignore
         "textual": flag,
         "proportional": flag,
     }
-    option_spec = images.Image.option_spec.copy()
+    option_spec = images.Image.option_spec.copy() if images.Image.option_spec is not None else {}
     option_spec.update(own_option_spec)
 
     def run(self) -> list[nodes.Node]:
@@ -103,7 +103,7 @@ def run(self) -> list[nodes.Node]:
         if isinstance(image_node, nodes.system_message):
             return [image_node]
         text = "\n".join(self.content)
-        image_node.aafig = {"options": aafig_options, "text": text}
+        image_node.aafig = {"options": aafig_options, "text": text}  # type: ignore[attr-defined]
         return [image_node]