refactor: Don't try to download artifacts in ProblemResolverSuite

The tests often timeout if coursier with retries is involved and besides mtags are not published aside from 2.13.x so this will always fail.

Author: tgodzik

tests/unit/src/main/scala/tests/BaseLspSuite.scala

@@ -56,7 +56,7 @@ abstract class BaseLspSuite(
   protected def useVirtualDocuments = useVirtualDocs
 
   protected def mtagsResolver: MtagsResolver =
-    new TestMtagsResolver
+    new TestMtagsResolver(checkCoursier = true)
 
   override def afterAll(): Unit = {
     if (server != null) {

tests/unit/src/main/scala/tests/TestMtagsResolver.scala

@@ -10,16 +10,19 @@ import scala.meta.internal.metals.ScalaVersions
  * For `unit` we don't publish mtags at all but there are some tests that trigger docker check.
  * So for these cases, do fallback on previous mechanic by checking declared supported versions.
  */
-class TestMtagsResolver extends MtagsResolver {
+class TestMtagsResolver(checkCoursier: Boolean) extends MtagsResolver {
 
   val default: MtagsResolver = MtagsResolver.default()
 
+  private def localCheck(scalaVersion: String) =
+    if (ScalaVersions.isSupportedAtReleaseMomentScalaVersion(scalaVersion))
+      Some(MtagsBinaries.BuildIn)
+    else None
+
   override def resolve(scalaVersion: String): Option[MtagsBinaries] = {
-    default.resolve(scalaVersion).orElse {
-      if (ScalaVersions.isSupportedAtReleaseMomentScalaVersion(scalaVersion))
-        Some(MtagsBinaries.BuildIn)
-      else None
-    }
+    if (checkCoursier)
+      default.resolve(scalaVersion).orElse(localCheck(scalaVersion))
+    else localCheck(scalaVersion)
   }
 
   override def isSupportedInOlderVersion(version: String): Boolean =

tests/unit/src/main/scala/tests/TestScala3Compiler.scala

@@ -19,7 +19,7 @@ object TestScala3Compiler {
   def compiler(name: String, input: InputProperties)(implicit
       ec: ExecutionContext
   ): Option[PresentationCompiler] = {
-    val resolver = new TestMtagsResolver()
+    val resolver = new TestMtagsResolver(checkCoursier = true)
     resolver.resolve(V.scala3) match {
       case Some(mtags: MtagsBinaries.Artifacts) =>
         val time = new FakeTime

tests/unit/src/test/scala/tests/troubleshoot/ProblemResolverSuite.scala

@@ -228,7 +228,7 @@ class ProblemResolverSuite extends FunSuite {
 
       val problemResolver = new ProblemResolver(
         AbsolutePath(workspace),
-        new TestMtagsResolver,
+        new TestMtagsResolver(checkCoursier = false),
         () => None,
         () => javaHome,
         () => isTestExplorerProvider,