Snark conquers all in ‘Deadpool 2,’ a superhero sequel that’s more of the same

It’s not easy to capture lightning in a bottle twice, and it’s even harder to push boundaries when you’re playing it safe.

In “Deadpool 2,” the manic antics fly fast, but the franchise loses its edge as wise-cracking antihero Deadpool goes dadcore, attempting to infuse standard-issue four-quadrant…