use Scala 2.12 by default

Author: bburdiliak

build.sbt

@@ -6,7 +6,7 @@ val scala213 = "2.13.11"
 val scala3 = "3.2.2"
 
 ThisBuild / organization := "io.cequence"
-ThisBuild / scalaVersion := scala3
+ThisBuild / scalaVersion := scala212
 ThisBuild / version := "1.0.0"
 ThisBuild / isSnapshot := false