Add mypy

[samwaseda]

Let's see what happens.

[github-actions]

👈 Launch a binder notebook on branch pyiron/pyiron_snippets/mypy

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.13%. Comparing base (6c47c6c) to head (3c35d3f).
⚠️ Report is 11 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #50      +/-   ##
==========================================
+ Coverage   95.10%   95.13%   +0.02%     
==========================================
  Files          13       13              
  Lines         552      555       +3     
==========================================
+ Hits          525      528       +3     
  Misses         27       27              

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[liamhuber]

Super. I was worried the factory would be much nastier to get mypy compliant. Thanks, @samwaseda!