Only add the CI skipping label on initial commit. (#7545)
Only add the CI skipping label on initial commit. (#7545)

For two reasons:

1) The git status command we use to detect the files about to be added won't see any files that weren't amended, and may reach the wrong conclusion.

2) Even if we fix 1), the user may have concluded that they want to delete that label and force a CI anyway, for whatever reason, and we don't want to keep overriding that.
wisechengyi/pants,tdyas/pants,pantsbuild/pants,wisechengyi/pants,pantsbuild/pants,pantsbuild/pants,benjyw/pants,pantsbuild/pants,pantsbuild/pants,tdyas/pants,wisechengyi/pants,pantsbuild/pants,twitter/pants,twitter/pants,jsirois/pants,wisechengyi/pants,tdyas/pants,benjyw/pants,tdyas/pants,tdyas/pants,wisechengyi/pants,benjyw/pants,twitter/pants,twitter/pants,twitter/pants,pantsbuild/pants,twitter/pants,tdyas/pants,tdyas/pants,wisechengyi/pants,tdyas/pants,jsirois/pants,wisechengyi/pants,benjyw/pants,wisechengyi/pants,benjyw/pants,twitter/pants,jsirois/pants,tdyas/pants,benjyw/pants,wisechengyi/pants,benjyw/pants,twitter/pants,twitter/pants