nbqa adedd to pre-commit, added black and ruff for notebooks

[davorrunje]

Why are these changes needed?

Ruff and black are being run on python files by pre-commit, but not on notebooks. Nbqa can be used to perform the same on the notebooks as well. This PR adds nbqa command to pre-commit.

Related issue number

Closes #1170

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (3680197) 31.92% compared to head (16c79a1) 41.64%.
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1171      +/-   ##
==========================================
+ Coverage   31.92%   41.64%   +9.71%     
==========================================
  Files          29       29              
  Lines        4097     4097              
  Branches      955     1006      +51     
==========================================
+ Hits         1308     1706     +398     
+ Misses       2695     2219     -476     
- Partials       94      172      +78     

Flag	Coverage Δ
unittests	41.54% <ø> (+9.66%)	⬆️

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