Automerge: [Github] Remove call to llvm-project-tests.yml from spirv-tests.yml

This will eventually allow for removing llvm-project-tests.yml. This
should significantly reduce the complexity of these workflows at the
cost of a little bit of duplication standard to github actions.

Reviewers: michalpaszkowski, sudonatalie

Reviewed By: sudonatalie

Pull Request: llvm/llvm-project#153869

Author: boomanaiden154