Update emoji set to Unicode 15 (#25595)
Update emoji set to Unicode 15 which was added upstream here:
https://github.com/github/gemoji/commit/cb5c514d472daf9b312c963987f4d7ee865c28fe
<img width="854" alt="Screenshot 2023-06-29 at 11 02 56 AM"
src="https://github.com/go-gitea/gitea/assets/1669571/7bfb663d-0804-4d23-a62d-f585a6783ca6">
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Co-authored-by: silverwind <me@silverwind.io>
authored by