Update MDK with new output from mod generator

Author: neoforge-mdk-automation[bot]

gradle.properties

@@ -18,7 +18,7 @@ minecraft_version=1.20.5
 # as they do not follow standard versioning conventions.
 minecraft_version_range=[1.20.5]
 # The Neo version must agree with the Minecraft version to get a valid artifact
-neo_version=20.5.21-beta
+neo_version=
 # The loader version range can only use the major version of FML as bounds
 loader_version_range=[1,)