Run tests also on Python3.10

[dweindl]

Waiting for sbmlteam/libCombine#46

[codecov-commenter]

Codecov Report

Merging #88 (709806e) into develop (7a2ac6e) will increase coverage by 0.06%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop      #88      +/-   ##
===========================================
+ Coverage    79.70%   79.76%   +0.06%     
===========================================
  Files           26       26              
  Lines         2941     2941              
  Branches       709      713       +4     
===========================================
+ Hits          2344     2346       +2     
+ Misses         422      421       -1     
+ Partials       175      174       -1     

Impacted Files	Coverage Δ
petab/lint.py	78.74% <0.00%> (+0.59%)	⬆️

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