[llvm] [Github] Explicitly requesting Ubuntu 22.04 for SPIRV test (PR #122395)

[Adam Yang via llvm-commits]

adam-yang wrote:

> > Looks like there's a real problem with some spirv tests, maybe spirv-tools versions changed or something and is rejecting some SPIRV that was passing validation before.
> 
> Is it failing at tip of tree too? If they are, it's probably good to land this patch and then fix forward the new failures. If I had to guess I would say the failures also exist at ToT, but there are always weird edge cases when trying to make CI work.

Yes it repros on tip of tree too. I'm pretty sure latest changes in SPIRV-Tools just broke these tests because the errors don't repro when I use an older release tag of SPIRV-Tools. I haven't pinpointed which commit broke it yet.

I'll just check this change in and resolve the SPIRV-Tools issue separately.

https://github.com/llvm/llvm-project/pull/122395