Remove allocated test for CS%uhtr

Removed allocated tests for the potentially statically allocated arrays CS%uhtr and CS%vhtr in a newly added line testing whether there are OBCs in use that would require a halo update on these arrays.  Even in dynamic memory mode, these arrays are always being allocated, so these tests served no purpose, but in static memory mode they led to compile time errors.  All answers are bitwise identical.

src/core/MOM.F90

@@ -1436,7 +1436,7 @@ subroutine step_MOM_tracer_dyn(CS, G, GV, US, h, Time_local)
                       CS%tracer_diff_CSp, CS%tracer_Reg, CS%tv)
   if (CS%debug) call MOM_tracer_chksum("Post-diffuse ", CS%tracer_Reg, G)
   if (showCallTree) call callTree_waypoint("finished tracer advection/diffusion (step_MOM)")
-  if (associated(CS%OBC) .and. allocated(CS%uhtr) .and. allocated(CS%vhtr)) then
+  if (associated(CS%OBC)) then
     call pass_vector(CS%uhtr, CS%vhtr, G%Domain)
     call update_segment_tracer_reservoirs(G, GV, CS%uhtr, CS%vhtr, h, CS%OBC, &
                      CS%t_dyn_rel_adv, CS%tracer_Reg)