Trump can still ask for a recount per Georgia law, and no doubt he will. It's highly unlikely it will change anything, but there'll be a recount there. (The second count was an audit of results; state law requires that a race be recounted, the choice of such to be made by the Secretary of State, and Raffensberger chose the Presidential race due to its close margin and significance.)
It'll be interesting to see how the Senate runoffs play out. My suspicion is that while Biden's win in Georgia wouldn't have been conceivable without Abrams' efforts in voter registration, what tipped the balance was people who voted Republican on all races except the Presidential race, where they voted for Biden, Jorgensen, or nobody at all. So that's enough to put Georgia in the Democratic column for the Electoral College, but won't be enough to flip either Senate seat.
I wonder what the registration rules are for the runoffs.
EDIT:
https://www.cbc.ca/news/world/pennsylvania-vote-certification-trump-biden-1.5811628A Trump campaign effort to prevent certification of Pennsylvania's results has been thrown out of court.