Remove some unnecessary type assertions.

Author: 12wrigja

lib/calendar.ts

@@ -785,7 +785,7 @@ abstract class HelperBase {
     return calendarDate;
   }
   validateCalendarDate(calendarDate: Partial<FullCalendarDate>): asserts calendarDate is FullCalendarDate {
-    const { era, month, year, day, eraYear, monthCode, monthExtra } = calendarDate as Partial<FullCalendarDate>;
+    const { era, month, year, day, eraYear, monthCode, monthExtra } = calendarDate;
     // When there's a suffix (e.g. "5bis" for a leap month in Chinese calendar)
     // the derived class must deal with it.
     if (monthExtra !== undefined) throw new RangeError('Unexpected `monthExtra` value');
@@ -2082,7 +2082,7 @@ abstract class ChineseBaseHelper extends HelperBase {
   abstract override id: BuiltinCalendarId;
   calendarType = 'lunisolar' as const;
   inLeapYear(calendarDate: CalendarYearOnly, cache: OneObjectCache) {
-    const months = this.getMonthList(calendarDate.year, cache as OneObjectCache);
+    const months = this.getMonthList(calendarDate.year, cache);
     return ObjectEntries(months).length === 13;
   }
   monthsInYear(calendarDate: CalendarYearOnly, cache: OneObjectCache) {

lib/ecmascript.ts

@@ -594,7 +594,7 @@ export function ParseTemporalInstant(isoString: string) {
   if (!z && !offset) throw new RangeError('Temporal.Instant requires a time zone offset');
   // At least one of z or offset is defined, but TS doesn't seem to understand
   // that we only use offset if z is not defined (and thus offset must be defined).
-  // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+  // eslint-disable-next-line @typescript-eslint/no-non-null-assertion, @typescript-eslint/no-unnecessary-type-assertion
   const offsetNs = z ? 0 : ParseTimeZoneOffsetString(offset!);
   ({ year, month, day, hour, minute, second, millisecond, microsecond, nanosecond } = BalanceISODateTime(
     year,