ci: Adds autopush to dockerhub on commit

[frgfm]

This PR introduces the following modifications:

• adds a docker build + push on "latest" tag on each commit (vs. each release before)
• adds additional build jobs for the client to spot problems with some OS or python versions
• fixes pypi & conda jobs for release

[codecov[bot]]

Codecov Report

Merging #303 (9554cea) into main (626ec3a) will increase coverage by 0.23%. The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #303      +/-   ##
==========================================
+ Coverage   94.71%   94.95%   +0.23%     
==========================================
  Files          66       63       -3     
  Lines        1590     1505      -85     
==========================================
- Hits         1506     1429      -77     
+ Misses         84       76       -8     

Flag	Coverage Δ
client	?
unittests	94.95% <ø> (ø)

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see 3 files with indirect coverage changes