Bump Scala 2.12.16 to 2.12.18 for JDK21

Author: dfurmans

build.sbt

@@ -30,7 +30,7 @@ ThisBuild / homepage := Some(
 
 // Scala versions
 
-val scala212 = "2.12.16"
+val scala212 = "2.12.18"
 val scala213 = "2.13.12"
 val scala3 = "3.3.1"