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

[Aiden Grossman 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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boomanaiden154 wrote:

Are you sure you want to change this to pull request target? That will cause the workflow to just build the `main` branch (or whatever the target branch is) rather than the PR branch.

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