fix(datetime): do not report timezone in ionChange (#26183)

resolves #25577

BREAKING CHANGE:

Datetime no longer incorrectly reports the time zone when `value` is updated. Datetime does not manage time zones, so any time zone information provided is ignored.

core/src/components/datetime/datetime-interface.ts

@@ -19,7 +19,6 @@ export interface DatetimeParts {
   hour?: number;
   minute?: number;
   ampm?: 'am' | 'pm';
-  tzOffset?: number;
 }
 
 export type DatetimePresentation = 'date-time' | 'time-date' | 'date' | 'time' | 'month' | 'year' | 'month-year';