[llvm] workflows: Run spirv tests on self-hosted runner (PR #77025)

[Tom Stellard via llvm-commits]

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@@ -12,7 +12,7 @@ on:
       - 'llvm/**'
       - '.github/workflows/llvm-tests.yml'
       - '.github/workflows/llvm-project-tests.yml'
-  pull_request:
+  pull_request_target:
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tstellar wrote:

No, I was just trying to see if that would fix the error.  I've reverted that change now.

https://github.com/llvm/llvm-project/pull/77025