Function getEndOfYear

getEndOfYear(date?): Date | undefined
Returns the end year date of the given date
Parameters
- Optionaldate: Date
  the date to inspect
Returns Date | undefined
the end year date of the given date
Example
```
getEndOfYear(new Date(2023, 8, 30));    // Date(2023, 11, 31, 23, 59, 59)
```