chore(deps): Update dependency net.neoforged:neoforge to v21.9.16-beta

Author: renovate[bot]

gradle/libs.versions.toml

@@ -14,7 +14,7 @@ immutables = "2.11.4"
 minecraft = "1.21.9"
 fabricLoader = "0.17.2"
 fabricPermissionsApi = "0.5.0"
-neoforge = "21.9.15-beta"
+neoforge = "21.9.16-beta"
 neoform = "1.21.9-20250930.151910"
 adventureMod = "6.7.0"