Fix StackOverflowError when reporting self-referencing exceptions

Problem

When an exception has a circular reference in its cause chain (e.g., exception.getCause() == exception), sbt throws a StackOverflowError while trying to report the exception. This happens because StackTrace.trimmedLines traverses the cause chain without checking for circular references.

This is problematic because some libraries or frameworks may create exceptions with self-referencing causes, and sbt should be resilient to such edge cases.

Solution

This PR adds circular reference detection to StackTrace.trimmedLines using an IdentityHashMap-backed Set, similar to how the JDK handles this in Throwable.printStackTrace().

When a circular reference is detected, instead of recursing infinitely, the method now appends a [CIRCULAR REFERENCE: ...] message to indicate the cycle.

Changes

• Modified StackTrace.trimmedLines to track seen exceptions using IdentityHashMap
• Added check to detect circular references before processing each cause
• When circular reference is detected, append informative message instead of recursing
• Added unit tests for:
  • Normal exceptions
  • Exceptions with causes
  • Self-referencing exceptions
  • Circular exception chains

Example Output

For a self-referencing exception, the output now looks like:

java.lang.RuntimeException: self-referencing exception
	at ...
[CIRCULAR REFERENCE: java.lang.RuntimeException: self-referencing exception]

Fixes #7509

Contribution by Gittensor, see my contribution statistics at https://gittensor.io/miners/details?githubId=94194147