Remove unused max-line-length argument in flake8

It doesn't matter because we are ignoring E501

Author: ricardoV94

setup.cfg

@@ -1,7 +1,6 @@
 [flake8]
 select = C,E,F,W
 ignore = E203,E231,E501,E741,W503,W504,C901
-max-line-length = 88
 per-file-ignores =
     **/__init__.py:F401,E402,F403
     pytensor/tensor/linalg.py:F401,F403