Have you tried using get-pip.py to reinstall pip?

I would recommend reading about get-pip.py first before doing this, but the process shouldn't be difficult.

https://pip.pypa.io/en/stable/installation/

1. Download get-pip.py (assuming windows 11, powershell)

wget -uri https://bootstrap.pypa.io/get-pip.py -OutFile get-pip.py

alternatively you could use save as the file and save it to your machine.

2. Install pip

python get-pip.py

Full output:

PS C:\Users\Jerem> python get-pip.py
Collecting pip
  Using cached pip-23.3.2-py3-none-any.whl.metadata (3.5 kB)
Using cached pip-23.3.2-py3-none-any.whl (2.1 MB)
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 23.3.2
    Uninstalling pip-23.3.2:
      Successfully uninstalled pip-23.3.2
Successfully installed pip-23.3.2

Test that its working

PS C:\Users\Jerem> python -m pip --version
pip 23.3.2 from C:\Users\Jerem\AppData\Local\Programs\Python\Python311\Lib\site-packages\pip (python 3.11)