bump minimum cftime version for compatability

Author: andrew-s28

pixi.toml

@@ -49,7 +49,7 @@ uxarray = "==2025.3.0"
 dask = "==2024.5.1"
 zarr = "==2.15.0"
 xgcm = "==0.9.0"
-cftime = "==1.3.1"
+cftime = "==1.6.3"
 
 [feature.py311.dependencies]
 python = "3.11.*"