chore: update changelog.md to include v1.39.4

[aaron-prindle]

Not a traditional release: v1.39.4 commit as this is released from the v1 branch

test failures related to #8079, not this PR

[codecov]

Codecov Report

Merging #8078 (af9beaf) into main (290280e) will decrease coverage by 3.97%.
The diff coverage is 53.46%.

@@            Coverage Diff             @@
##             main    #8078      +/-   ##
==========================================
- Coverage   70.48%   66.50%   -3.98%     
==========================================
  Files         515      597      +82     
  Lines       23150    29165    +6015     
==========================================
+ Hits        16317    19396    +3079     
- Misses       5776     8331    +2555     
- Partials     1057     1438     +381     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/credits/export.go	0.00% <0.00%> (ø)
cmd/skaffold/app/cmd/deploy.go	40.90% <0.00%> (-12.94%)	⬇️
cmd/skaffold/app/cmd/test.go	44.44% <0.00%> (ø)
cmd/skaffold/app/exitcode.go	100.00% <ø> (+6.66%)	⬆️
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/render.go	35.48% <18.18%> (-5.90%)	⬇️
cmd/skaffold/app/cmd/lsp.go	28.12% <28.12%> (ø)
cmd/skaffold/app/cmd/run.go	64.28% <33.33%> (-9.63%)	⬇️
cmd/skaffold/app/cmd/fix.go	56.41% <37.50%> (-20.07%)	⬇️
... and 394 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more