fixup! Merge branch 'cv/global-core-worker' into cv/task-arg-by-value

Ray.jl/src/runtime.jl

@@ -40,7 +40,6 @@ Currently only used to get the next job ID.
 This is set during `init` and used there to get the Job ID for the driver.
 """
 const GLOBAL_STATE_ACCESSOR = Ref{ray_jll.GlobalStateAccessor}()
-const CORE_WORKER = Ref{ray_jll.CoreWorker}()
 
 # env var to control whether logs are sent do stderr or to file.  if "1", sent
 # to stderr; otherwise, will be sent to files in `/tmp/ray/session_latest/logs/`
@@ -105,7 +104,6 @@ function init(runtime_env::Union{RuntimeEnv,Nothing}=nothing;
     atexit(ray_jll.shutdown_driver)
 
     _init_global_function_manager(gcs_address)
-    CORE_WORKER[] = ray_jll.GetCoreWorker()
 
     return nothing
 end