Fix flake on CI

Author: r9y9

setup.py

@@ -74,6 +74,7 @@ def find_version(*file_paths: str) -> str:
             "flake8>=3.7,<4",
             "flake8-bugbear",
             "isort>=4.3,<5.2.0",
+            "importlib-metadata<5.0",
         ],
         "test": ["pytest"],
         "demo": ["streamlit>=0.86.0", "stqdm"],