add barebones placeholder tests

Author: ksimpson-work

cuda_core/tests/__init__.py

@@ -1,8 +1,5 @@
 from cuda.py._launcher import LaunchConfig
 
-def kernel():
-    pass
-
 def test_launch_initialization():
     config = LaunchConfig(grid=(1, 1, 1), block=(1, 1, 1), stream=None, shmem_size=0)