Set reference version to 3.3.1 (#18585)

Author: bishabosha

project/Build.scala

@@ -83,7 +83,7 @@ object DottyJSPlugin extends AutoPlugin {
 object Build {
   import ScaladocConfigs._
 
-  val referenceVersion = "3.3.1-RC7"
+  val referenceVersion = "3.3.1"
 
   val baseVersion = "3.4.0-RC1"
 
@@ -101,7 +101,7 @@ object Build {
    *  set to 3.1.3. If it is going to be 3.1.0, it must be set to the latest
    *  3.0.x release.
    */
-  val previousDottyVersion = "3.3.0"
+  val previousDottyVersion = "3.3.1"
 
   object CompatMode {
     final val BinaryCompatible = 0