Disable spotless on Forge

FG 6 does not support Gradle 9 and FG 7 is not out yet.

Author: Yeregorix

.github/workflows/check-spotless.yaml

@@ -11,5 +11,5 @@ jobs:
     uses: SpongePowered/.github/.github/workflows/shared-check-spotless.yaml@master
     with:
       runtime_version: 25
-      extra_gradle_params: "-Pprojects=vanilla,forge,neoforge,testplugins"
+      extra_gradle_params: "-Pprojects=vanilla,neoforge,testplugins"
     secrets: inherit