Add pyproj to environment dependencies

PROJ library isn't picked up during.rtd build

Author: kmuehlbauer

environment.yml

@@ -14,6 +14,7 @@ dependencies:
   - nbconvert
   - notebook
   - numpy
+  - pyproj
   - pytest
   - pytest-sugar
   - pytest-xdist
@@ -22,4 +23,4 @@ dependencies:
   - sphinx-copybutton
   - sphinx-book-theme>=1.0
   - wradlib >=2.4, <2.5
-  - xarray >=2024.10.0
+  - xarray >=2024.10.0