Update scala3-library to 3.7.0-RC3 (#3638)

Author: scala-steward

project/deps.sc

@@ -11,7 +11,7 @@ object Scala {
   def scala3NextPrefix = "3.6"
   def scala3Next       = s"$scala3NextPrefix.4" // the newest/next version of Scala
   def scala3NextAnnounced   = scala3Next  // the newest/next version of Scala that's been announced
-  def scala3NextRc          = "3.7.0-RC2" // the latest RC version of Scala Next
+  def scala3NextRc          = "3.7.0-RC3" // the latest RC version of Scala Next
   def scala3NextRcAnnounced = "3.7.0-RC1" // the latest announced RC version of Scala Next
 
   // The Scala version used to build the CLI itself.