sphinx-bootstrap-theme-0.4.14 isn't compatible with py39

[Vinicius Arcanjo]

sphinx-bootstrap-theme-0.4.14 isn't compatible with py39, this library sphinx_bootstrap_theme on requirements.txt needs to be updated just so developers can build the docs with make locally

Collecting sphinx>=1.5.6
  Using cached Sphinx-4.5.0-py3-none-any.whl (3.1 MB)
Collecting sphinx-autobuild>=0.7.1
  Using cached sphinx_autobuild-2021.3.14-py3-none-any.whl (9.9 kB)
Collecting sphinx-rtd-theme>=0.2.4
  Using cached sphinx_rtd_theme-1.0.0-py2.py3-none-any.whl (2.8 MB)
Collecting sphinx_bootstrap_theme==0.4.14
  Using cached sphinx-bootstrap-theme-0.4.14.tar.gz (1.1 MB)
  Preparing metadata (setup.py) ... error
  error: subprocess-exited-with-error

  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [1 lines of output]
      error in sphinx-bootstrap-theme setup command: use_2to3 is invalid.
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.
WARNING: You are using pip version 22.0.4; however, version 22.1.1 is available.
You should consider upgrading via the '/home/viniarck/repos/documentation/tutorials/.diren
v/python-3.9.12/bin/python3.9 -m pip install --upgrade pip' command.