[build] Fix CI Build Tag (again)

Minor format earmarks, but the only functional change that caused behavior difference here is the removal of tab inside the ifdef. The canonical format is without tab - confusingly the way this was historically with the tab did work, but only when it was after the line 23 COMMIT?= (which confuses me since unrelated, but seems likely weird make internals).

In any case this is hopefully the last stick-poke 🤞