Function isZoneUnset

isZoneUnset(zone: unknown): boolean
Check if a Zone is the library's sentinel "unset" value.

The library uses a special Zone instance to represent unknown/unset timezones since Luxon doesn't officially support unset zones.
Parameters
- zone: unknown
  Zone instance to check
Returns boolean
true if the zone is the UnsetZone sentinel value
See
Example
```
isZoneUnset(UnsetZone)                    // true
isZoneUnset(Info.normalizeZone("UTC"))    // false
isZoneUnset(Info.normalizeZone("UTC+8"))  // false
```
- Defined in src/Timezones.ts:229