[Metal] Buffer robustness failure in 64 bit InterlockedAdd test

[bob80905]

In the link below the error is seen:

project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/InterlockedAdd.int64.test.tmp.o
Validation Warning: [ mvk-warn ]
VK_ERROR_FEATURE_NOT_PRESENT: Metal does not support buffer robustness.

gpu-exec: error: Compilation failed due to an interrupted connection: XPC_ERROR_CONNECTION_INTERRUPTED. This error occurred after multiple retries.: 

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https://github.com/llvm/offload-test-suite/actions/runs/25528342754/job/74928931859?pr=1163#step:13:117

This was seen on check-hlsl-mtl.