Ensure Windows console color enablement

[briandealwis]

Fixes: #4783

Description

Explicitly call mattn/go-colorable's colorable.EnableColorsStdout() to ensure Windows consoles are placed in a mode to decipher ANSI colour sequences.

In #3757, we switched to using heroku/color to provide colour definitions. Although heroku/color uses mattn/go-colorable, it doesn't call EnableColorsStdout(), and besides we are just using heroku/color's colour definitions rather than their console output and io.Writer wrappers.

Before:

After:

[codecov]

Codecov Report

Merging #4798 into master will decrease coverage by 2.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #4798      +/-   ##
==========================================
- Coverage   73.85%   71.83%   -2.02%     
==========================================
  Files         347      347              
  Lines       13796    11873    -1923     
==========================================
- Hits        10189     8529    -1660     
+ Misses       2972     2725     -247     
+ Partials      635      619      -16     

Impacted Files	Coverage Δ
pkg/skaffold/color/formatter.go	90.00% <100.00%> (ø)
pkg/skaffold/trigger/workdir.go	20.00% <0.00%> (-13.34%)	⬇️
pkg/skaffold/initializer/analyze/directory.go	50.00% <0.00%> (-10.00%)	⬇️
pkg/diag/validator/resource.go	50.00% <0.00%> (-8.83%)	⬇️
pkg/skaffold/logfile/logfile.go	71.42% <0.00%> (-8.58%)	⬇️
pkg/skaffold/runner/debugging.go	66.66% <0.00%> (-8.34%)	⬇️
pkg/skaffold/deploy/resource/status.go	77.77% <0.00%> (-7.94%)	⬇️
pkg/skaffold/runner/portforwarder.go	22.22% <0.00%> (-7.78%)	⬇️
pkg/skaffold/runner/render.go	12.50% <0.00%> (-7.50%)	⬇️
pkg/skaffold/util/term.go	42.85% <0.00%> (-7.15%)	⬇️
... and 338 more

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