Undefined name: minor -> self.hash
[flake8](http://flake8.pycqa.org) testing of https://github.com/google/skywater-pdk on Python 3.8.3
$ __flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics__
```
./scripts/python-skywater-pdk/skywater_pdk/base.py:332:71: F821 undefined name 'minor'
return (self.milestone, self.major, self.minor, self.commits, minor)
^
1 F821 undefined name 'minor'
1
```
https://flake8.pycqa.org/en/latest/user/error-codes.html
On the flake8 test selection, this PR does _not_ focus on "_style violations_" (the majority of flake8 error codes that [__psf/black__](https://github.com/psf/black) can autocorrect). Instead these tests are focus on runtime safety and correctness:
* E9 tests are about Python syntax errors usually raised because flake8 can not build an Abstract Syntax Tree (AST). Often these issues are a sign of unused code or code that has not been ported to Python 3. These would be compile-time errors in a compiled language but in a dynamic language like Python they result in the script halting/crashing on the user.
* F63 tests are usually about the confusion between identity and equality in Python. Use ==/!= to compare str, bytes, and int literals is the classic case. These are areas where __a == b__ is True but __a is b__ is False (or vice versa). Python >= 3.8 will raise SyntaxWarnings on these instances.
* F7 tests logic errors and syntax errors in type hints
* F82 tests are almost always _undefined names_ which are usually a sign of a typo, missing imports, or code that has not been ported to Python 3. These also would be compile-time errors in a compiled language but in Python a __NameError__ is raised which will halt/crash the script on the user.1 file changed
