adjust to icalendar 6.0.0 changes

Author: KoljaWindeler

custom_components/isc/manifest.json

@@ -3,7 +3,7 @@
   "name": "ics",
   "documentation": "https://github.com/KoljaWindeler/ics/blob/master/README.md",
   "config_flow": true,
-  "version": "20250113.01",
+  "version": "20250114.01",
   "requirements": [
     "recurring-ical-events",
     "icalendar>=6.0.0",