Don't override editable installation

[frostming]

Pull Request Check List

• A news fragment is added in news/ describing what is new.
• Test cases added for changed code.

Describe what you have changed in this PR.

[codecov-commenter]

Codecov Report

Merging #1011 (85b5c3e) into main (2f3ff2d) will increase coverage by 0.39%.
The diff coverage is 74.07%.

@@            Coverage Diff             @@
##             main    #1011      +/-   ##
==========================================
+ Coverage   83.50%   83.89%   +0.39%     
==========================================
  Files          73       73              
  Lines        6439     6453      +14     
  Branches     1336     1342       +6     
==========================================
+ Hits         5377     5414      +37     
+ Misses        745      711      -34     
- Partials      317      328      +11     

Flag	Coverage Δ
unittests	83.65% <74.07%> (+0.39%)	⬆️

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

Impacted Files	Coverage Δ
pdm/cli/actions.py	79.45% <33.33%> (-0.44%)	⬇️
pdm/installers/synchronizers.py	84.84% <75.00%> (+0.30%)	⬆️
pdm/models/candidates.py	90.00% <100.00%> (-0.04%)	⬇️
pdm/resolver/providers.py	94.95% <100.00%> (+0.08%)	⬆️
pdm/models/setup.py	52.96% <0.00%> (+10.27%)	⬆️

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