fix: generated build constants

Author: FllipEis

registration-velocity/build.gradle.kts

@@ -2,6 +2,12 @@ plugins {
     alias(libs.plugins.minotaur)
 }
 
+kotlin {
+    sourceSets.main {
+        kotlin.srcDir(layout.buildDirectory.dir("generated/source/buildConfig"))
+    }
+}
+
 dependencies {
     api(project(":registration-shared"))
     compileOnly("com.velocitypowered:velocity-api:3.4.0-SNAPSHOT")
@@ -50,4 +56,4 @@ modrinth {
     loaders.add("velocity")
     changelog.set("https://docs.simplecloud.app/changelog")
     syncBodyFrom.set(rootProject.file("README.md").readText())
-}
+}