fix: upgrade yaml library to go-yaml v3 over buildkite

[ecrupper]

Follow up from go-vela/types#386

And also fixing the tests that were broken from go-vela/types#387

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.91%. Comparing base (efd5b04) to head (f98f0b5).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1171   +/-   ##
=======================================
  Coverage   52.91%   52.91%           
=======================================
  Files         550      550           
  Lines       19162    19162           
=======================================
  Hits        10139    10139           
  Misses       8459     8459           
  Partials      564      564           

Files	Coverage Δ
api/types/string.go	85.71% <ø> (ø)
compiler/native/compile.go	71.63% <ø> (ø)
compiler/native/parse.go	86.51% <ø> (ø)
compiler/native/substitute.go	69.23% <ø> (ø)
compiler/template/native/convert.go	90.90% <ø> (ø)
compiler/template/native/render.go	85.71% <ø> (ø)
compiler/template/starlark/render.go	47.16% <ø> (ø)
mock/server/pipeline.go	0.00% <ø> (ø)

[KellyMerrick]

lgtm