Update Github Actions

[gaborbernat]

• Use latest pre-commit action
• Retry via bash OS install commands
• Move from deadsnakes to Github powered python3.9
• Move from 3.8 to 3.9.0-rc.2
• Move from pep517.build to build project

[codecov]

Codecov Report

Merging #1957 into main will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1957      +/-   ##
==========================================
- Coverage   93.92%   93.91%   -0.02%     
==========================================
  Files          86       86              
  Lines        4228     4237       +9     
==========================================
+ Hits         3971     3979       +8     
- Misses        257      258       +1     

Flag	Coverage Δ
#tests	93.91% <ø> (-0.02%)	⬇️

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

Impacted Files	Coverage Δ
src/virtualenv/seed/embed/base_embed.py	96.22% <0.00%> (-1.89%)	⬇️
src/virtualenv/activation/via_template.py	100.00% <0.00%> (ø)

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