drop special behavior to support Go pre-1.13

[imjasonh]

No description provided.

[codecov-commenter]

Codecov Report

Merging #446 (e1e5449) into main (08c6c71) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #446      +/-   ##
==========================================
- Coverage   53.25%   53.23%   -0.03%     
==========================================
  Files          37       36       -1     
  Lines        1842     1841       -1     
==========================================
- Hits          981      980       -1     
  Misses        710      710              
  Partials      151      151              

Impacted Files	Coverage Δ
pkg/build/gobuild.go	58.35% <100.00%> (ø)

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