Tomcat server vulnerabilites

Hi,

The current sync-endpoint:latest image appears to be using Tomcat 8.5.100, but 8.5.xx reached end-of-life in March 2024

I’ll try to see if I can fix it and make a pull request, but It would also be nice if anyone who knows more about server security (and the sync endpoint setup) would take a look at it.

Best regards
Arthur