Fix isolation of presubmit tools

[abitrolly]

Otherwise they are still installed in ~/go/bin.

[codecov-commenter]

Codecov Report

Merging #1306 (ee673f2) into main (86e1c81) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1306   +/-   ##
=======================================
  Coverage   74.01%   74.01%           
=======================================
  Files         112      112           
  Lines        8386     8386           
=======================================
  Hits         6207     6207           
  Misses       1575     1575           
  Partials      604      604           

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