Hi,
Based on the information provided, the sale of the gold took place before you were resident in the UK, that is, in the Hong Kong part of the split year 2022/23, and you would not therefore have to declare any capital gain arising to HMRC. Please however read the detailed statutory residence test notes to ensure that you have correctly applied the residency rules to your circumstances.
RDR3: Statutory Residence Test (SRT) notes
Thank you.