fix: add type: ignore for caldav ssl_verify_cert parameter

caldav types declare ssl_verify_cert as Union[bool, str] but the value
is passed through to httpx which accepts ssl.SSLContext. Add type: ignore
annotation to satisfy the ty type checker in CI.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

nextcloud_mcp_server/client/calendar.py

@@ -36,7 +36,7 @@ class CalendarClient:
             url=f"{base_url}/remote.php/dav/",
             username=username,
             auth=auth,
-            ssl_verify_cert=get_nextcloud_ssl_verify(),
+            ssl_verify_cert=get_nextcloud_ssl_verify(),  # type: ignore[arg-type]  # caldav types say bool|str but passes through to httpx which accepts SSLContext
         )
         self._calendar_home_url = f"{base_url}/remote.php/dav/calendars/{username}/"