Setting version to 2.0.20

@rtyley using gha-scala-library-release-workflow · @rtyley using gha-scala-library-release-workflow · commit 8e0375e0b8ac · 2024-01-17T11:25:48.000Z
diff --git a/version.sbt b/version.sbt
@@ -1 +1 @@
-ThisBuild / version := "2.0.20-SNAPSHOT"
+ThisBuild / version := "2.0.20"
