Entrapment is coercing someone into committing a crime they wouldn’t have otherwise.
This was a honeypot. A bait for those who were already looking to cheat.
There’s no evidence that those who cheated were already going to.
The prof said it was only suspected that students were cheating, and instead of investigating and collecting evidence, he fabricated evidence through his own encouragement of the same crime he seeks to denounce.
Entrapment is basically associated with an implied threat, with that threat people do things they normally wouldn’t, if there was no threat then it’s less likely to be considered entrapment.
Also entrapment only matters for criminal justice, you getting fucked at university for cheating isn’t going to care about how entrapment works.