[minor] Remove get_global_worker(), RuntimeContext (#7638)

python/ray/runtime_context.py

@@ -1,30 +0,0 @@
-import ray.worker
-
-
-class RuntimeContext:
-    """A class used for getting runtime context."""
-
-    def __init__(self, worker=None):
-        self.worker = worker
-
-    @property
-    def current_driver_id(self):
-        """Get current driver ID for this worker or driver.
-
-        Returns:
-            If called by a driver, this returns the driver ID. If called in
-                a task, return the driver ID of the associated driver.
-        """
-        assert self.worker is not None
-        return self.worker.current_job_id
-
-
-_runtime_context = None
-
-
-def _get_runtime_context():
-    global _runtime_context
-    if _runtime_context is None:
-        _runtime_context = RuntimeContext(ray.worker.get_global_worker())
-
-    return _runtime_context