Add support Jetty 12

[zeitlinger]

Spring Boot 3.2 uses Jetty 12 - to get full jetty support.

[trask]

otherwise you don't get any server spans

I thought the servlet instrumentation would create the server span if the app server specific instrumentation didn't already?

[zeitlinger]

otherwise you don't get any server spans

I thought the servlet instrumentation would create the server span if the app server specific instrumentation didn't already?

No, apparently that doesn't happen - I've checked that in a test

[breedx-splk]

otherwise you don't get any server spans

I thought the servlet instrumentation would create the server span if the app server specific instrumentation didn't already?

No, apparently that doesn't happen - I've checked that in a test

I'm also surprised by this result, and while yes sure, we should support the latest Jetty, I think it would be helpful to understand why the servlet instrumentation didn't kick in.

[zeitlinger]

Turns out my test was misleading - we get a different server span, rather than no span at all.