[llvm] [SPIR-V] Fix removeCapabilityIf not pruning MinimalCaps (PR #206478)

[Arseniy Obolenskiy via llvm-commits]

aobolensk wrote:

> Can we add a test-case where we check that the pruned capability is no longer emitted too ?
> 
> Everything else looks good to me.

Yes, done

https://github.com/llvm/llvm-project/pull/206478