Update networkx.yaml for Summer 2023 meeting time (#386)

The new meeting time will be 11am PDT starting May 17, 2023.

Author: dschult

calendars/networkx.yaml

@@ -7,10 +7,10 @@ events:
 
       Meeting Link:  https://colgate.zoom.us/j/92619161786
       Meeting notes: https://hackmd.io/ea2IhUuqSrG4kM9tokXuEw
-    begin: 2023-01-10 09:30:00
-    end: 2023-01-10 10:30:00
+    begin: 2023-05-17 11:00:00
+    end: 2023-05-17 12:00:00
     url: https://colgate.zoom.us/j/92619161786
     repeat:
       interval:
         days: 7
-      until: 2025-08-26 00:00:00
+      until: 2025-12-31 00:00:00