Restore python3.4 support (add it back to CI)

[gaborbernat]

Resolves #1963

[codecov]

Codecov Report

Merging #1965 into main will increase coverage by 0.00%.
The diff coverage is 85.71%.

@@           Coverage Diff           @@
##             main    #1965   +/-   ##
=======================================
  Coverage   93.93%   93.94%           
=======================================
  Files          86       86           
  Lines        4239     4246    +7     
=======================================
+ Hits         3982     3989    +7     
  Misses        257      257           

Flag	Coverage Δ
#tests	93.94% <85.71%> (+<0.01%)	⬆️

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

Impacted Files	Coverage Δ
...virtualenv/seed/embed/via_app_data/via_app_data.py	82.35% <0.00%> (-0.18%)	⬇️
src/virtualenv/util/path/_pathlib/__init__.py	93.93% <91.66%> (+52.27%)	⬆️
src/virtualenv/seed/wheels/acquire.py	100.00% <100.00%> (ø)
...ualenv/create/via_global_ref/builtin/pypy/pypy2.py	92.20% <0.00%> (-6.50%)	⬇️
...ualenv/create/via_global_ref/builtin/pypy/pypy3.py	94.87% <0.00%> (-5.13%)	⬇️
src/virtualenv/info.py	95.00% <0.00%> (-5.00%)	⬇️
src/virtualenv/seed/embed/base_embed.py	96.22% <0.00%> (-1.89%)	⬇️
src/virtualenv/util/path/_pathlib/via_os_path.py	89.62% <0.00%> (-1.89%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update adcf327...3e2740b. Read the comment docs.