docs: self-host the star history chart

GitHub restricted the stargazers API to repository admins and
collaborators on 2026-06-30, which broke star-history.com's embedded
charts for anyone who is not a collaborator on the repo being charted —
including the chart that was in this README.

Points the badge at a self-hosted equivalent instead. Same idea, same
data, served from a chart service I run rather than a third party, so it
does not break again when someone else's quota or policy changes.

Refs: https://github.blog/changelog/2026-06-30-upcoming-access-restrictions-to-public-api-endpoints-and-ui-views/

Author: vietanhdev

README.md

@@ -152,7 +152,7 @@ If you want to contribute to **AnyLabeling**, please read [Contribution Guidelin
 
 ## Star history
 
-[![Star History Chart](https://api.star-history.com/svg?repos=vietanhdev/anylabeling&type=Date)](https://star-history.com/#vietanhdev/anylabeling&Date)
+[![Star History Chart](https://www.vietanh.dev/api/stars/vietanhdev/anylabeling.svg)](https://github.com/vietanhdev/anylabeling/stargazers)
 
 ## References