Update to Jetty 12

[cowwoc]

Is your task related to a problem? Please describe

Jetty 11 has not been actively supported since 2023

Describe the solution you'd like

Upgrade to Jetty 12

Describe alternatives you've considered

No response

Additional context

No response

[cowwoc]

My main codebase depends on Jetty 12 so I'd love to use Jetty as the underlying connector for this library to reduce the dependency size and reduce the number of moving parts. Unfortunately, I don't think I can use JettyHttpClientFactory until you update the dependencies because the latter will try using the Jetty 11 API against Jetty 12 and it's likely to run into runtime failures.

[manusa]

Requires Java 17.

This issue requires setting up again the dual release mode where some modules are released with Java17 support while the main modules are released using Java11.

Then, we can decide if we bump Jetty to 12 or preserve the current module and add a new one to minimize breakages.