chore: set mmlc version to stable 1.21.0

RobinTheHood · RobinTheHood · commit 986a8db2d65a · 2023-06-22T13:18:17.000+02:00
diff --git a/config/version.json b/config/version.json
@@ -1 +1 @@
-{"version": "1.21.0-beta.3"}
+{"version": "1.21.0"}
