flake8-html cannot be packed by pyinstaller

* flake8-html version: 0.4.3
* flake8 version: 6.0.0
* Python version: 3.9.7 64 bit
* Operating System: Windonws OS

### Description

We developed a SW to do code inspection. The flake8 and flake8-html works well. However, we tried to using pyinstaller to pack flake8-html , the flake8-html reported error. Seems that the flake8_html cannot be packed. Is there some kind of restriction here? Or any settings we should do?
Pyinstaller version: 5.3
Package command:
pyinstaller -F setup.py

### What I Did
```
Traceback (most recent call last):
File "setup.py", line 4, in
import flake8_html
File "", line 1007, in _find_and_load
File "", line 986, in _find_and_load_unlocked
File "", line 680, in _load_unlocked
File "PyInstaller\loader\pyimod02_importers.py", line 493, in exec_module
File "flake8_html\__init__.py", line 9, in
```

Start with setup.py and flake8_html/__init__.py at the reported line 9. Reproduce the failure with Python 3.9, PyInstaller 5.3, and the shown pyinstaller -F setup.py command, then inspect the complete traceback. Done means the packaging restriction or required configuration is identified and the supported outcome is documented or fixed.

Written by the indexing model from the issue text.