Reduce the stack trace output in tests (#13088)

- followup #13044

Changelog:
- update: move the logic that prints stack traces to a separate `DebugSuite` to reduce the test output

Author: 4e6

engine/runtime-integration-tests/src/test/scala/org/enso/interpreter/test/instrument/RuntimeAsyncCommandsTest.scala

@@ -14,7 +14,7 @@ import org.enso.polyglot.runtime.Runtime.Api.{
 import org.enso.runtime.utils.ThreadUtils
 import org.enso.text.{ContentVersion, Sha3_224VersionCalculator}
 import org.enso.text.editing.model
-import org.enso.testkit.FlakySpec
+import org.enso.testkit.{DebugSpec, FlakySpec}
 import org.graalvm.polyglot.Context
 import org.scalatest.BeforeAndAfterEach
 import org.scalatest.flatspec.AnyFlatSpec
@@ -30,6 +30,7 @@ class RuntimeAsyncCommandsTest
     extends AnyFlatSpec
     with Matchers
     with BeforeAndAfterEach
+    with DebugSpec
     with FlakySpec {
 
   // === Test Utilities =======================================================

lib/scala/testkit/src/main/scala/org/enso/testkit/DebugSpec.scala

@@ -0,0 +1,21 @@
+package org.enso.testkit
+
+import org.enso.runtime.utils.ThreadUtils
+import org.scalatest._
+
+/** Trait provides debug information when a test fails in the suite. */
+trait DebugSpec extends TestSuite {
+
+  override def withFixture(test: NoArgTest): Outcome = {
+    val result = super.withFixture(test)
+
+    if (result.isFailed || result.isCanceled) {
+      val msg = ThreadUtils.dumpAllStacktraces(
+        s"Thread dump of the failed test `${test.name}`"
+      )
+      println(msg)
+    }
+
+    result
+  }
+}

lib/scala/testkit/src/main/scala/org/enso/testkit/FlakySpec.scala

@@ -1,6 +1,5 @@
 package org.enso.testkit
 
-import org.enso.runtime.utils.ThreadUtils
 import org.scalatest._
 
 /** Trait is used to mark the tests in the suite as _flaky_ and make them
@@ -21,16 +20,7 @@ trait FlakySpec extends TestSuite {
   object SkipOnFailure extends Tag("org.enso.test.skiponfailure")
 
   override def withFixture(test: NoArgTest): Outcome = {
-    val result = super.withFixture(test)
-
-    if (result.isFailed || result.isCanceled) {
-      val msg = ThreadUtils.dumpAllStacktraces(
-        s"Thread dump of the failed flaky test `${test.name}`"
-      )
-      println(msg)
-    }
-
-    result match {
+    super.withFixture(test) match {
       case Failed(_) | Canceled(_)
           if Flaky.isEnabled && test.tags.contains(Flaky.name) =>
         Pending