Release Scala 3.8.0-RC3

Signed-off-by: Wojciech Mazur <wmazur@virtuslab.com>

Author: WojciechMazur

project/Build.scala

@@ -80,7 +80,7 @@ object Build {
    *  During release candidate cycle incremented by the release officer before publishing a subsequent RC version;
    *  During final, stable release is set exactly to `developedVersion`.
   */
-  val baseVersion = s"$developedVersion-RC2"
+  val baseVersion = s"$developedVersion-RC3"
 
   /** The version of TASTY that should be emitted, checked in runtime test
    *  For defails on how TASTY version should be set see related discussions: