ci: add tests in CI for windows python v3.9

[oboulant]

This PR

• removes from .github/workflows/run-test.yml the explicit bypass of tests for Windows and Python v3.9. At some point in the past, we had to bypass those because Python v3.9 and Windows intersection could not setup correctly (tests could not run). Now, the intersection Windows x Python v3.9 seems more mature and tests can run
• merges both .github/workflows/run-test.yml and .github/workflows/run-test-coverage.yml into a single .yml with two jobs

[codecov]

Codecov Report

Merging #219 (741ecce) into master (111bfe7) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #219    +/-   ##
=======================================
  Coverage        0   0.00%            
=======================================
  Files           0      40    +40     
  Lines           0     973   +973     
=======================================
- Misses          0     973   +973     

Flag	Coverage Δ
unittests	0.00% <ø> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/ruptures/detection/kernelcpd.py	0.00% <0.00%> (ø)
src/ruptures/base.py	0.00% <0.00%> (ø)
src/ruptures/detection/pelt.py	0.00% <0.00%> (ø)
src/ruptures/metrics/hausdorff.py	0.00% <0.00%> (ø)
src/ruptures/metrics/randindex.py	0.00% <0.00%> (ø)
src/ruptures/metrics/hamming.py	0.00% <0.00%> (ø)
src/ruptures/datasets/__init__.py	0.00% <0.00%> (ø)
src/ruptures/costs/costrbf.py	0.00% <0.00%> (ø)
src/ruptures/detection/dynp.py	0.00% <0.00%> (ø)
src/ruptures/show/__init__.py	0.00% <0.00%> (ø)
... and 30 more

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[deepcharles]

LGTM