So far as I know, no federal judge anywhere has ruled that the 2020 presidential election in any state was fraudulent to the point where the results should be decertified. Evidence appears to exist but has yet to be validated in a court of law, and until that happens there will be no decertification, nor should there be. I'm not even sure any federal or state judge even has the grounds or authority to do that, there has to be a legal basis upon which a judge can base his/her ruling for a decertification, and I do not know if such a legal basis exists in any state Constitution. It is certainly not there in the US Constitution, nor as far as I know in any federal or state statue.
A judge may at some point rule that a person(s) broke state law (maybe even federal law) during that election and face criminal charges and punishment, but does that rise to the conclusion that the election results were fraudulent to the extent that requires decertification? Upon what metric does a judge do that, any judge? Judges are not supposed to make up the laws, that's called judicial activism and that contradicts the separation of powers upon which our gov't exists. I do not see that as happening; a state legislature may declare that election to be fraudulent in their state, they can do that. But if they were to decertify that election, then that's another story. It would surely wind up in court as it should, so where in that state's Constitution can they base their decertification on? Constitutions at the federal and state levels are written to enumerate what the gov't can do, and if it ain't in there then they can't do it unless a court says they can (see Row v Wade).
I think that the states may indeed pass legislation regarding future elections and possible decertification. For now though, no basis exists for that action (decert) and frankly no evidence exists (IMHO) that will stand up in a court of law as sufficient proof that the election was fraudulent of the point of decertifying it. I think it's reasonable to believe that fraud did indeed take place and that it was not insignificant. BUT - as yet there has been no lawsuit in court where a judge rules a decertification is warranted. I say that as a person who voted for Trump, but according to the laws of the land he lost.
So, fix the state laws to try to eliminate or reduce fraud. If people broke the law then charge and give them a trial and see where it goes. Maybe even lay the groundwork in a state(s) to decertify an election if certain stringent parameters are met, cuz we don't need to go through this shit again. But do it legally, with the force of law. Prove it.