Revert "Set baseVersion to 3.5.1-RC1" (#20402)

Reverts #20392

Closes #20401

Author: Kordyjan

project/Build.scala

@@ -85,7 +85,7 @@ object Build {
 
   val referenceVersion = "3.4.2-RC1"
 
-  val baseVersion = "3.5.1-RC1"
+  val baseVersion = "3.5.0-RC1"
 
   // LTS or Next
   val versionLine = "Next"