Do not install cuda-toolkit (#665)

cuda-toolkit pulls a lot of dependencies. The environment we generate should match our needs, and if the users want to, they can install the full cuda-toolkit.

Author: marcinz

scripts/generate-conda-envs.py

@@ -96,7 +96,6 @@ def conda(self) -> Reqs:
             deps += (f"cudatoolkit={self.ctk_version}",)
         else:
             deps += (
-                f"cuda-toolkit={self.ctk_version}",
                 "cuda-cccl",  # no cuda-cccl-dev package exists
                 "cuda-cudart-dev",
                 "cuda-cudart-static",