Default JDK change: revert or yell from the mountaintops

[rossabaker]

The default JDK changed from 8 to 11 in 0.14.0, which isn't noted in the changelog and probably not what most people want. Lots of people are getting Scala Steward upgrades to sbt-spiewak-0.23 and ending up on Temurin 11, and probably not realizing it.

[mdedetrich]

My argument to this would be that if you don't want JDK to update itself to the latest LTS release then you can set githubWorkflowJavaVersions and it will never happen. For majority of software, updating to latest LTS JDK release is desirable and githubWorkflowJavaVersions exists to override this behaviour.

I also don't see how this is any different to, lets say, JDK versions silently updating when using github actions (i.e. you specify JDK 11 but not the minor version, and this will also silently update whenever the github action does).