always use --index-url

[pmeier]

Closes #123

[codecov]

Codecov Report

Merging #141 (122c3e4) into main (d914a8e) will decrease coverage by 0.1%.
The diff coverage is 100.0%.

@@           Coverage Diff           @@
##            main    #141     +/-   ##
=======================================
- Coverage   80.0%   79.9%   -0.1%     
=======================================
  Files          6       6             
  Lines        380     379      -1     
=======================================
- Hits         304     303      -1     
  Misses        76      76             

Flag	Coverage Δ
unit	79.9% <100.0%> (-0.1%)	⬇️

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

Files Changed	Coverage Δ
light_the_torch/_patch.py	69.9% <100.0%> (-0.2%)	⬇️