Add back mpas_tools lower bound

Author: xylar

conda/dev.yml

@@ -18,7 +18,7 @@ dependencies:
   - beautifulsoup4
   - lxml
   - matplotlib-base >=3.8.2
-  - mpas_tools
+  - mpas_tools >=0.21.0
   - netcdf4
   - numpy >=2.0,<3.0
   - output_viewer=1.3.3