Update file_ops.py

Author: OeGiaretta

manim/utils/file_ops.py

@@ -198,7 +198,7 @@ def open_file(file_path: Path, in_browser: bool = False) -> None:
     if current_os == "Windows":
         # The method os.startfile is only available in Windows,
         # ignoring type error caused by this.
-        os.startfile(file_path if not in_browser else file_path.parent)
+        os.startfile(file_path if not in_browser else file_path.parent) # type: ignore[attr-defined]
     else:
         if current_os == "Linux":
             commands = ["xdg-open"]