Merge pull request #15290 from dotty-staging/reference-version-3.1.3-RC4

Set reference version to 3.1.3-RC4

Author: Kordyjan

project/Build.scala

@@ -57,7 +57,7 @@ object DottyJSPlugin extends AutoPlugin {
 object Build {
   import ScaladocConfigs._
 
-  val referenceVersion = "3.1.3-RC3"
+  val referenceVersion = "3.1.3-RC4"
 
   val baseVersion = "3.2.0-RC1"