dependency: Update dependency com.velocitypowered:velocity-api to v3.4.0

Author: renovate[bot]

buildSrc/src/main/kotlin/Versions.kt

@@ -10,7 +10,7 @@ object Versions {
     const val AWAITILITY = "4.3.0"
 
     const val SPIGOT_API = "1.21.4-R0.1-SNAPSHOT"
-    const val VELOCITY_API = "3.4.0-SNAPSHOT"
+    const val VELOCITY_API = "3.4.0"
 
     const val JETBRAINS_ANNOTATIONS = "26.0.2-1"