Upgrade okhttp3 to 4.x for kamon-prometheus

[t-bast]

Kamon currently depends on an old version of okhttp3 (see Build.scala):

val okHttp            = "com.squareup.okhttp3"  %  "okhttp"          % "3.14.7"

This creates issues with other packages such as com.softwaremill.sttp.client3:okhttp-backend who have upgraded to okhttp3 version 4.9.3: adding a dependency to kamon-prometheus effectively downgrades the okhttp package in my class path, which breaks my application.

It would be really nice to upgrade Kamon to the latest version of okhttp3, is this something you could consider?

[eyalfa]

hi, we've encountered this issue due to compliance requirements (see square/okhttp#6724).

we were able to mitigate by simply introducing the latest okhttp version as a direct dependency of our application, tested by accessing the kamon-prometheus endpoint in a browser).

will you guys be willing to accept a (tiny) PR increasing okhttp version?