2 Actions
Spell Components are usually the same as the number of Actions to cast a spell. Indeed, it was explicitly so during the Pathfinder 2e Playtest. However, there is no longer a rule linking Components to Actions.
Removing Somatic Components still has benefits. You can cast the spell while bound, and you do not provoke most Reactions, notably unmodified Attack of Opportunity, because it does not have the Manipulate trait.
Incidentally, I don't see any reason why you couldn't "consider" it to be two Verbal components if you would like to add flavor and justify the second action. Nothing about the Concentrate trait nor Verbal prevents you from supplying it twice in the same turn or Cast a Spell action.
Your GM would have to make a decision about whether that constitutes two different opportunities for Reactions, though, in the rare case that a creature has a Reaction for Concentrate effects and the ability to use it twice. Fighters with Disruptive Stance and Combat Reflexes is one example of such an enemy.