Update Externals to tag for MAPL 2.0

MAPL 2.0 fvdycore is now tagged `geos/v1.1.0`

Author: mathomp4

Externals.cfg

@@ -2,7 +2,7 @@
 required = True
 repo_url = git@github.com:GEOS-ESM/GFDL_atmos_cubed_sphere.git
 local_path = ./@fvdycore
-branch = geos/MAPL-2.0
+tag = geos/v1.1.0
 protocol = git
 
 [externals_description]