Harry Potter but without Voldemort reappearing during his school years.

Quirrel is still going for the stone, but doesn't have Voldemort on the back of his head/isn't trying to get it for Voldemort.

The Basilisk is still getting out, but there is no diary, Tom Riddle just didn't put it into longterm stasis after he "caught" hagrid, and now the Basilisk is just going through the school to find food because the tunnel into the forest/lake has collapsed or is too small for its current size to use (space expansion runes got worn off from the snake scales constantly rubbing against them) with the message about the "enemies of the heir" actually is a prank after someone else found and hung up the petrified/dead(? Would they be able to tell?) Mrs Norris on the floor.

Sirius did still escape after seeing Scabbers/Wormtail, and wormtail does still get away, but doesn't find Voldemort for years/hides first?

Someone does still enter Harry into the TWT, but it is in the hopes of killing him. On a slight plus side, Harry is the Hogwarts Champion not a fourth Champion, on the negative he is still called a cheater, and he's getting sabotaged instead of helped behind the scenes. Whether this is still somehow Barty Junior, or if it is Pettigrew who entered Harry to try and kill him to take that feat back with him should Voldemort return is up in the air.

Fifth year without the "Voldemort is back" would be the first to really have divergence, but could still have Umbridge/the ministry making a move on Hogwarts/Dumbledore for some other contrived reasoning/bureaucratic corruption.

Sixth Year could have a Death Eater escape from Azkaban as they saw how Sirius escaped and one or more manage to use some method to take an animagus form without the "quick" way of the potion (probably Rookwood and/or Bellatrix) and they break out the others. They spend the rest of the year recovering, and possibly still assault Hogwarts/end with Dumbledore still ending up dead.

Seventh year has tensions rising and the escapees make moves in the dark, and work to track down their master/find a way to bring him back with Harry's graduation possibly being interrupted by him getting portkeyed to the graveyard/being forced into being part of the resurrection before he makes his escape.

The (shadow?) war ramps up after graduation, but while several friends are still in their last Year at Hogwarts (Luna and Ginny), possibly having Hogsmeade, the Express, or King's Cross attacked during a break. Potentially as a diversion to attack the Ministry as well, but could still end with students dead/as hostages as the war goes loud.