[scala3] Fix compiler warnings, NFC (#5080)

Fix Scala3 compilation warnings, except those related to private bundle
constructors.

Signed-off-by: Schuyler Eldridge <[email protected]>

Author: seldridge

core/src/main/scala/chisel3/internal/Builder.scala

@@ -930,11 +930,6 @@ private[chisel3] object Builder extends LazyLogging {
     throwException(m)
   }
 
-  def getScalaMajorVersion: Int = {
-    val "2" :: major :: _ :: Nil = chisel3.BuildInfo.scalaVersion.split("\\.").toList
-    major.toInt
-  }
-
   def useLegacyWidth: Boolean = dynamicContextVar.value.map(_.useLegacyWidth).getOrElse(false)
 
   def includeUtilMetadata: Boolean = dynamicContextVar.value.map(_.includeUtilMetadata).getOrElse(false)
@@ -1067,9 +1062,8 @@ private[chisel3] object Builder extends LazyLogging {
       errors.checkpoint(logger)
       logger.info("Done elaborating.")
 
-      val typeAliases = aliasMap.flatMap {
-        case (name, (underlying: fir.Type, info: SourceInfo)) => Some(DefTypeAlias(info, underlying, name))
-        case _                                                => None
+      val typeAliases = aliasMap.flatMap { case (name, (underlying: fir.Type, info: SourceInfo)) =>
+        Some(DefTypeAlias(info, underlying, name))
       }.toSeq
 
       /** Stores an adjacency list representation of layers.  Connections indicating children. */

core/src/main/scala/chisel3/internal/firrtl/IR.scala

@@ -471,7 +471,7 @@ private[chisel3] object ir {
   sealed abstract class LayerConfig
   object LayerConfig {
     final case class Extract(outputDir: Option[String]) extends LayerConfig
-    final case object Inline extends LayerConfig
+    case object Inline extends LayerConfig
   }
 
   final case class Layer(

firrtl/src/main/scala/firrtl/ir/IR.scala

@@ -484,7 +484,7 @@ sealed abstract class LayerConfig
 @deprecated("All APIs in package firrtl are deprecated.", "Chisel 7.0.0")
 object LayerConfig {
   final case class Extract(outputDir: Option[String]) extends LayerConfig
-  final case object Inline extends LayerConfig
+  case object Inline extends LayerConfig
 }
 
 @deprecated("All APIs in package firrtl are deprecated.", "Chisel 7.0.0")

firrtl/src/main/scala/firrtl/ir/Serializer.scala

@@ -494,7 +494,6 @@ object Serializer {
   private def s(node: Direction)(implicit b: StringBuilder, indent: Int): Unit = node match {
     case Input  => b ++= "input"
     case Output => b ++= "output"
-    case other  => b ++= other.serialize // Handle user-defined nodes
   }
 
   private def s(node: Port)(implicit b: StringBuilder, indent: Int): Unit = node match {
@@ -519,7 +518,6 @@ object Serializer {
     case RawStringParam(name, value) =>
       b ++= name; b ++= " = "
       b += '\''; b ++= value.replace("'", "\\'"); b += '\''
-    case other => b ++= other.serialize // Handle user-defined nodes
   }
 
   private def s(node: TestParam)(implicit b: StringBuilder, indent: Int): Unit = node match {
@@ -540,7 +538,6 @@ object Serializer {
         b ++= name; b ++= " = "; s(value(name))
       }
       b ++= "}"
-    case other => b ++= other.serialize // Handle user-defined nodes
   }
 
   private def sIt(node: DefModule)(implicit indent: Int): Iterator[String] = node match {

svsim/src/main/scala/Workspace.scala

@@ -489,7 +489,7 @@ final class Workspace(
           .replace("$", "$$")
           .replace("'", "'\\''")
           .replace(workingDirectoryPath, "$(shell pwd)")
-      l("\t\t'", sanitizedArugment, "' \\")
+        l("\t\t'", sanitizedArugment, "' \\")
       }
       l("'-F' \\")
       l(s"\t\t'${sourceFilesFilelistWriter.path}'")
@@ -519,7 +519,7 @@ final class Workspace(
       l("simulationEnvironment = \\")
       for (((name, value), index) <- simulationEnvironment.zipWithIndex) {
         val sanitizedValue = value.replace(workingDirectoryPath, "$(shell pwd)")
-      l("\t", name, "=", sanitizedValue, if (index != simulationEnvironment.length - 1) " \\" else "")
+        l("\t", name, "=", sanitizedValue, if (index != simulationEnvironment.length - 1) " \\" else "")
       }
       l()
       //format: on

svsim/src/main/scala/vcs/Backend.scala

@@ -49,7 +49,7 @@ object Backend {
       case object TMerge extends XProp
     }
 
-    final object TraceSettings {
+    object TraceSettings {
       final case class FsdbSettings(verdiHome: String)
     }
     final case class TraceSettings(