When running tests `WITH_GTESTS` and `WITH_GPU_DRAW_TESTS` the
GPUShaderCreateInfo's specfically created for the tests could not be
found. This failed running tests on any backend.
This PR fixes this. The root cause what that the name of the compile
directive was incorrect. It should have been `WITH_GTESTS` but was
`WITH_GTEST`.
Pull Request: https://projects.blender.org/blender/blender/pulls/131956