proposal: increase maximum allowed python line length to 100 or 120

[danceratopz]

Currently, execution-spec-test's black and isort are configured with line-length=79. This is the recommended value in PEP8 and the Google Python Style Guide uses a length of 80. PEP8 does state however:

Some teams strongly prefer a longer line length. For code maintained exclusively or primarily by a team that can reach agreement on this issue, it is okay to increase the line length limit up to 99 characters, provided that comments and docstrings are still wrapped at 72 characters.

Within @ethereum:

• The Snake Charmers use 100,
• The execution-specs codebase is configured to 80.
• The consensus-specs codebase is configured to use 120 (see e.g. blob/dev/tests/generators/kzg_4844/main.py).

I'd propose to increase line length as soon as the pytest refactor is complete, #116.

If there is some uncertainty whether to choose 100 or 120 we could format the codebase with both in order to make a better decision.