Don't point to the compiler backlog when a compiler plugin phase crashes

[Gedochao]

Compiler version

3.6.1-RC1-bin-20241014-69ac5fb-NIGHTLY

Description

Currently, when a compiler plugin phase crashes, we still point the user to the Scala compiler backlog.
For example, a crash with stainless produces output like this:

An unhandled exception was thrown in the compiler.
  Please file a crash report here:
  https://github.com/scala/scala3/issues/new/choose
  For non-enriched exceptions, compile with -Xno-enrich-error-messages.

     while compiling: BugReport.scala
        during phase: stainless
                mode: Mode(ImplicitsEnabled)
     library version: version 2.13.14
    compiler version: version 3.5.0
            settings: -Wsafe-init true -classpath 

We should indicate to the user that they should raise the crash to the compiler plugin maintainers, rather than us.

Context

This is a follow-up issue to:

• standalone wait crashes compiler when invoked from Stainless #21758

Expectation

I'd expect output similar to:

An unhandled exception was thrown in the compiler.
  Please file a crash report in the compiler plugin backlog.
  The name of the compiler plugin which caused the crash is "stainless".
  For non-enriched exceptions, compile with -Xno-enrich-error-messages.

     while compiling: BugReport.scala
        during phase: stainless
                mode: Mode(ImplicitsEnabled)
     library version: version 2.13.14
    compiler version: version 3.5.0
            settings: -Wsafe-init true -classpath