Possibly not, but how does

[[ $GITHUB_HEAD_REF = "dev" ]]

make any sense? Shouldn't it be

[[ $GITHUB_HEAD_REF == "dev" ]]?

After all, it's a comparison - and single = are normally assignments. But there might be some hidden Bash sorcery at work that I don't understand...

See:

Introduced in f499c3f