chore: require f-strings

[JohnVillalovos]

We previously converted all string formatting to use f-strings. Enable
pylint check to enforce this.

[codecov-commenter]

Codecov Report

Merging #2043 (7fa19e0) into main (7327f78) will increase coverage by 5.32%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #2043      +/-   ##
==========================================
+ Coverage   88.89%   94.22%   +5.32%     
==========================================
  Files          78       78              
  Lines        4972     4972              
==========================================
+ Hits         4420     4685     +265     
+ Misses        552      287     -265     

Flag	Coverage Δ
cli_func_v4	82.54% <ø> (ø)
py_func_v4	80.91% <ø> (ø)
unit	85.25% <ø> (?)

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

Impacted Files	Coverage Δ
gitlab/base.py	100.00% <ø> (+20.85%)	⬆️
gitlab/exceptions.py	100.00% <0.00%> (+0.69%)	⬆️
gitlab/v4/objects/commits.py	94.87% <0.00%> (+1.28%)	⬆️
gitlab/v4/objects/packages.py	96.29% <0.00%> (+1.85%)	⬆️
gitlab/mixins.py	92.22% <0.00%> (+1.94%)	⬆️
gitlab/v4/objects/issues.py	89.15% <0.00%> (+2.40%)	⬆️
gitlab/v4/objects/events.py	98.73% <0.00%> (+2.53%)	⬆️
gitlab/cli.py	100.00% <0.00%> (+3.27%)	⬆️
gitlab/v4/objects/releases.py	100.00% <0.00%> (+3.84%)	⬆️
gitlab/v4/objects/environments.py	100.00% <0.00%> (+4.34%)	⬆️
... and 22 more