User Profile Time Zone doesn't take daylight saving time into account for Sydney

Issue Summary

Sydney observes DST(Daylight Saving) from the first Sunday in October to the first Sunday in April. During this period, Sydney's timezone is at GMT+11 instead of the standard GMT+10. However, Jira user profile does not account for daylight saving time, and it's showing GMT+10 instead of GMT+11 for Sydney:

There is no option to change it through updating user preferences Time-zone as GMT+11 is not available for selection under Australia region.

This is reproducible on Data Center: (yes) / (no)

Steps to Reproduce

1. Go to User Profile -> Preferences -> Update User Preferences
2. Select Region as Australia -> See the Time Zone option available for Sydney

Expected Results

During the DST period(from the first Sunday in October to the first Sunday in April), Sydney's timezone should be at GMT+11.

Actual Results

Sydney's timezone is at GMT+10 instead of the standard GMT+11 during DST.

Workaround

If you want to stop Jira from trying to accommodate DST, you can use the static GMT offset instead of Australia in TimeZone to see GMT+11 available for selection: