Compatibility with python 3.9

Adjust the type annotations to allow for usage with python 3.9.

Plan to deprecate 3.9 compatibility in October 2025 (end of support for 3.9)

pyproject.toml

 
 [project]
 name = "GeoSpatialTools"
-version = "0.6.0"
+version = "0.7.0"
 dependencies = [
     "numpy",
 ]