He never mentions the guy because the "assassination attempt" was a poorly disguised hoax, and EVERYONE knows it.
Worse for HitlerPig is that he KNOWS that everyone knows that it is a hoax, so he's keeping relatively quiet about it. Now and then he makes a reference to it, but it ALWAYS falls flat. Even his own followers don't get worked up about it because they know it was a clumsy hoax. If they claim to believe it, then they have to explain the fact that the guy was a hard-core MAGA, another awkward fact they don't want to deal with.
It was a hoax that didn't work, and one guy had his head literally blown off, so best to keep it on the DL.
I was recently reading that hard core right and Sociopathic Oligarchs all have a real weird thing for LotR. They give Tolkien names to lots of stuff. The article was very vague about why there is a connection ( I got the feeling that they really didn't know why it resonates with them), but it is there.