Fix issues in file_regrid.py and regrid_restart_file.py

gcpy/file_regrid.py
- Removed a double-flipping of vertical levels in LL -> CS/SG regridding

gcpy/regrid_restart_file.py
- Removed function check_lev_attribute, it is not defined

Signed-off-by: Bob Yantosca <yantosca@seas.harvard.edu>

gcpy/file_regrid.py

@@ -629,14 +629,6 @@ def regrid_ll_to_cssg(
             towards_common=False
         )
 
-        # Flip vertical levels (if necessary) and
-        # set the lev:positive attribute accordingly
-        dset = flip_lev_coord_if_necessary(
-            dset,
-            dim_format_in="classic",
-            dim_format_out=dim_format_out
-        )
-
         # Fix names and attributes of of coordinate variables depending
         # on the format of the ouptut grid (checkpoint or diagnostic).
         # Also convert the "diagnostic" grid to the "checkpoint" grid

gcpy/regrid_restart_file.py

@@ -533,8 +533,6 @@ def regrid_restart_file(
                 "Error when processing your stretched-grid parameters - are they correct?"
             ) from exception
 
-    dataset = check_lev_attribute(output_is_gchp)
-
     dataset.to_netcdf("new_restart_file.nc")
 
     info_message = "Wrote 'new_restart_file.nc' with %d variables"