`wiremock-jetty12` 3.x: upgrade jetty 12.1

Proposal

wiremock-jetty12 in the 3.x branch (current stable major release) is still using jetty 12.0.x, while the current version of jetty is 12.1.x. there are some incompatibilities between the two, thus using wiremock-jetty12 with jetty 12.1.x fails.

based on #2329 it seems that wiremock 4.0 is still quite a while away from being released.

would it be possible to create a new wiremock-jetty12 3.x release with jetty 12.1 compatibility?

References

workarounds were e.g. done in https://github.com/wiremock/wiremock-spring-boot/issues/137