FIX: Use new api to toggle top and right labels

[mgrover1]

Currently, when you create a plot using the GridMapDisplay, the plot returns the following error

/ccsopen/home/mgrover/mgrover/sail-radar-dev/lib/python3.9/site-packages/cartopy/mpl/gridliner.py:451: UserWarning: The .xlabels_top attribute is deprecated. Please use .top_labels to toggle visibility instead.
  warnings.warn('The .xlabels_top attribute is deprecated. Please '
/ccsopen/home/mgrover/mgrover/sail-radar-dev/lib/python3.9/site-packages/cartopy/mpl/gridliner.py:487: UserWarning: The .ylabels_right attribute is deprecated. Please use .right_labels to toggle visibility instead.
  warnings.warn('The .ylabels_right attribute is deprecated. Please '

This solves that issue by using the new, suggested methods

[zssherman]

Looks good to me!