Bump library/jetty from 11-jre17 to 12-jre17 in /src/server-qm

Bumps library/jetty from 11-jre17 to 12-jre17.

---
updated-dependencies:
- dependency-name: library/jetty
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

src/server-qm/Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/library/jetty:11-jre17
+FROM docker.io/library/jetty:12-jre17
 # WARNING DO NOT CHANGE WORKDIR or set it back to what it was before
 # $JETTY_BASE must be correct before starting Jetty