Object health does not register critical hit damage nor status effects, so one-tapping the Pylons is only influenced by damage and multishot. Therefore, a +Damage, +Multishot, -Harmless Riven is the best choice for this situation.

[Vile Acceleration] makes the weapon usable, as the base fire rate of the secondary fire mode is simply too low.

Vital sense is the next best-in-slot mod choice for unconditional, non-object health dps.

Critical delay would be the second-best mod choice for unconditional, non-object health dps... but we do not have a 10th mod slot to spare. Thankfully, there is a plethora of alternative ways to boost critical chance in Warframe (i.e. Arcane Avenger, Ardza's [Cat's Eye], Smeeta's [Charm], [Styanax]'s Passive, [Harrow]'s Covenant, etc.) such that leaving [Critical Delay] off the build is not detrimental.

Even without those alternative critical chance buffs, you will still deal plenty of DPS to the Profit Taker.