[llvm] [AMDGPU][NFC] Add GFX13 run lines to bitcast tests (PR #216980)

[Mariusz Sikora via llvm-commits]

mariusz-sikora-at-amd wrote:

> I don't think gfx13 changes the legal type set, so is this really necessary?

You're right. Now I see that bitcast behaves the same on gfx11/12/1250/13

https://github.com/llvm/llvm-project/pull/216980