flake8: Accept line up to 120 chars, exclude ninja/ninja_syntax.py

Since "ninja/ninja_syntax.py" is provided by ninja project and can be
installed in the source tree when installing an editable distribution, this
commit makes sure it is excluded.

Author: jcfr

setup.cfg

@@ -2,15 +2,15 @@
 test = pytest
 
 [flake8]
-max-line-length: 80
+max-line-length: 120
 # Whether to display the pep8 instructions on failure (can be quite verbose)
 show-pep8: False
 # Whether to show source code for each failure
 show-source: True
 # Maximum cyclomatic complexity allowed
 max-complexity: 14
 format: pylint
-exclude: .git,.idea,.eggs,__pycache__,.tox,_skbuild,src,versioneer.py
+exclude: .git,.idea,.eggs,__pycache__,.tox,_skbuild,src,versioneer.py,ninja/ninja_syntax.py
 
 [tool:pytest]
 testpaths = tests