[clang] [Clang][Sema] Tweak tryCaptureVariable for unevaluated lambdas (PR #93206)

[via cfe-commits]

https://github.com/cor3ntin commented:

I think it makes sense.
I kinda wish there would be a more generic way to skip over requires expressions but I also can't think of other contexts we'd want to skip over, so this looks fine. 

Thanks for fixing a large number of issues

https://github.com/llvm/llvm-project/pull/93206