Update requirements so xarray should work

Author: lmcinnes

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = datamapplot
-version = 0.6.1
+version = 0.6.2
 author = Leland McInnes
 author_email = leland.mcinnes@gmail.com
 maintainer = Leland McInnes
@@ -44,6 +44,7 @@ install_requires =
     scikit-image>=0.22
     scikit-learn>=1.1
     platformdirs
+    typing_extensions
 
 [options.entry_points]
 console_scripts =