[chore] Remove unused GetCallerId from Cython (#51327)

Signed-off-by: Kai-Hsun Chen <kaihsun@anyscale.com>

Author: kevin85421

python/ray/includes/libcoreworker.pxd

@@ -213,7 +213,6 @@ cdef extern from "ray/core_worker/core_worker.h" nogil:
         void SetActorTitle(const c_string &title)
         void SetActorReprName(const c_string &repr_name)
         void SetWebuiDisplay(const c_string &key, const c_string &message)
-        CTaskID GetCallerId()
         const ResourceMappingType &GetResourceIDs() const
         void RemoveActorHandleReference(const CActorID &actor_id)
         optional[int] GetLocalActorState(const CActorID &actor_id) const