ci: use consistent go build paths caching

[briandealwis]

Noticed the Windows tests weren't caching the go build or modules locations. Follow the suggestion here to use go env to retrieve the appropriate paths to cache.

[codecov]

Codecov Report

Merging #7044 (d1b641a) into main (290280e) will decrease coverage by 1.68%.
The diff coverage is 56.96%.

@@            Coverage Diff             @@
##             main    #7044      +/-   ##
==========================================
- Coverage   70.48%   68.79%   -1.69%     
==========================================
  Files         515      554      +39     
  Lines       23150    25868    +2718     
==========================================
+ Hits        16317    17797    +1480     
- Misses       5776     6866    +1090     
- Partials     1057     1205     +148     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/deploy.go	52.00% <ø> (-1.85%)	⬇️
cmd/skaffold/app/cmd/dev.go	84.61% <0.00%> (ø)
cmd/skaffold/app/cmd/render.go	36.66% <0.00%> (-4.72%)	⬇️
cmd/skaffold/skaffold.go	0.00% <0.00%> (ø)
cmd/skaffold/app/cmd/inspect_tests.go	62.50% <14.28%> (-1.14%)	⬇️
cmd/skaffold/app/cmd/lsp.go	28.12% <28.12%> (ø)
cmd/skaffold/app/cmd/fix.go	68.85% <40.00%> (-7.62%)	⬇️
cmd/skaffold/app/cmd/lint.go	42.85% <42.85%> (ø)
cmd/skaffold/app/cmd/find_configs.go	48.88% <50.00%> (+0.24%)	⬆️
cmd/skaffold/app/skaffold.go	76.19% <70.00%> (-8.43%)	⬇️
... and 183 more

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