Prevent workflow double trigger, Add PEP 561 compliance

[eddiebergman]

• Adds windows and mac to the unit tests but they are currently deactivate
• Removes duplicate triggers of tests with pull and push requests for other workflows.
• Fixes check for PEP 561 compliance with the dist
• Adds PEP 561 compliance (which I thought was there already but was not)

[codecov]

Codecov Report

Merging #1348 (79664b0) into development (887bb10) will decrease coverage by 0.17%.
The diff coverage is n/a.

@@               Coverage Diff               @@
##           development    #1348      +/-   ##
===============================================
- Coverage        88.02%   87.85%   -0.18%     
===============================================
  Files              140      140              
  Lines            10973    10959      -14     
===============================================
- Hits              9659     9628      -31     
- Misses            1314     1331      +17     

Impacted Files	Coverage Δ
...eline/components/feature_preprocessing/fast_ica.py	91.30% <0.00%> (-6.53%)	⬇️
...learn/pipeline/components/regression/libsvm_svr.py	85.22% <0.00%> (-5.69%)	⬇️
autosklearn/util/single_thread_client.py	90.90% <0.00%> (-2.28%)	⬇️
...ipeline/components/regression/gradient_boosting.py	91.42% <0.00%> (-1.97%)	⬇️
autosklearn/util/logging_.py	89.18% <0.00%> (-1.16%)	⬇️
...tosklearn/metalearning/metafeatures/metafeature.py	61.00% <0.00%> (-1.14%)	⬇️
autosklearn/ensemble_builder.py	85.85% <0.00%> (-0.99%)	⬇️
autosklearn/pipeline/components/base.py	78.78% <0.00%> (-0.26%)	⬇️
...sklearn/pipeline/components/regression/__init__.py	83.52% <0.00%> (-0.20%)	⬇️
...arn/pipeline/components/classification/__init__.py	84.94% <0.00%> (-0.17%)	⬇️
... and 19 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 887bb10...79664b0. Read the comment docs.

[mfeurer]

This looks like a very nice simplification of the workflows. I only have one small question.