[MNT] Update maximum argument count to 10
[MNT] Update maximum argument count to 10

Unidata/MetPy,Unidata/MetPy,ahaberlie/MetPy,ShawnMurd/MetPy,jrleeman/MetPy,ahaberlie/MetPy,dopplershift/MetPy,jrleeman/MetPy,dopplershift/MetPy