Fix update Star History widget with token

[josecelano]

Relates to: #1951

## Star History

<a href="https://www.star-history.com/?repos=torrust%2Ftorrust-tracker&type=date&logscale=&legend=top-left">
 <picture>
   <source media="(prefers-color-scheme: dark)" srcset="https://api.star-history.com/chart?repos=torrust/torrust-tracker&type=date&theme=dark&legend=top-left&sealed_token=EZxXVF9XAD8H2DhnWPfead9gIAICpoo6hryWYUlgQD8O8sumGOar4rnhl38CGJLKVB8MEX5G3u1SRvQG_zb4FB23WQbEeL9TKfHUS88RbQ6lHyQeK-EgIyz_oh2idrLePDHKsH1zyk489E1adJUnbrjdLs57Q9F7XKLqUH_cUSCjvSVnKbg9yRXd8Ktm" />
   <source media="(prefers-color-scheme: light)" srcset="https://api.star-history.com/chart?repos=torrust/torrust-tracker&type=date&legend=top-left&sealed_token=EZxXVF9XAD8H2DhnWPfead9gIAICpoo6hryWYUlgQD8O8sumGOar4rnhl38CGJLKVB8MEX5G3u1SRvQG_zb4FB23WQbEeL9TKfHUS88RbQ6lHyQeK-EgIyz_oh2idrLePDHKsH1zyk489E1adJUnbrjdLs57Q9F7XKLqUH_cUSCjvSVnKbg9yRXd8Ktm" />
   <img alt="Star History Chart" src="https://api.star-history.com/chart?repos=torrust/torrust-tracker&type=date&legend=top-left&sealed_token=EZxXVF9XAD8H2DhnWPfead9gIAICpoo6hryWYUlgQD8O8sumGOar4rnhl38CGJLKVB8MEX5G3u1SRvQG_zb4FB23WQbEeL9TKfHUS88RbQ6lHyQeK-EgIyz_oh2idrLePDHKsH1zyk489E1adJUnbrjdLs57Q9F7XKLqUH_cUSCjvSVnKbg9yRXd8Ktm" />
 </picture>
</a>