[llvm] [workflows] Only build native targets in ci-ubuntu-22.04 container (PR #94649)

[Tom Stellard via llvm-commits]

tstellar wrote:

I see the issue.  The 3 stages already build the native target only, but when llvm is built to generate the training data, it enables all the targets.  

https://github.com/llvm/llvm-project/pull/94649