Provide a fast CI option for draft status

[h-mayorquin]

This goes further than #1078.

The idea is the following. A two-tier CI depending on PR status (draft vs ready for review)

When the PR is on draft we only test on a minimal version of Python so simple errors can surface quickly.

Once the PR is ready for a review then we run the full python matrix to ensure that no error escapes the CI.

@pauladkisson thoughts?
I actually thought about going further and not run dev or live tests on draft but I first wanted to illustrate the idea.

https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/evaluate-expressions-in-workflows-and-actions#example

[pauladkisson]

I like this idea overall, just added a few suggestions.

[pauladkisson]

lgtm!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.44%. Comparing base (36464df) to head (33e735b).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1082   +/-   ##
=======================================
  Coverage   90.44%   90.44%           
=======================================
  Files         129      129           
  Lines        8055     8051    -4     
=======================================
- Hits         7285     7282    -3     
+ Misses        770      769    -1     

Flag	Coverage Δ
unittests	90.44% <ø> (+<0.01%)	⬆️

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