Update build version to 3.15.0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: tastybento

build.gradle.kts

@@ -46,7 +46,7 @@ paperweight.reobfArtifactConfiguration = io.papermc.paperweight.userdev.ReobfArt
 group = "world.bentobox" // From <groupId>
 
 // Base properties from <properties>
-val buildVersion = "3.14.2"
+val buildVersion = "3.15.0"
 val buildNumberDefault = "-LOCAL" // Local build identifier
 val snapshotSuffix = "-SNAPSHOT"  // Indicates development/snapshot version