relieve pandas <2 renstriction

Author: emanuel-schmid

requirements/env_climada.yml

@@ -17,7 +17,7 @@ dependencies:
   - netcdf4>=1.6
   - numba>=0.57
   - openpyxl>=3.1
-  - pandas>=1.5,<2.0  # 2.0 removed append and iteritems from DataFrame
+  - pandas>=1.5
   - pandas-datareader>=0.10
   - pathos>=0.3
   - pint>=0.22