update to Paper 26.2, Java 25 and Gradle 9.6.1

build.gradle

@@ -19,10 +19,10 @@ repositories {
 }
 
 dependencies {
-    compileOnly("io.papermc.paper:paper-api:1.21.11-R0.1-SNAPSHOT")
+    compileOnly("io.papermc.paper:paper-api:26.2.build.129-stable")
 }
 
-def targetJavaVersion = 21
+def targetJavaVersion = 25
 java {
     def javaVersion = JavaVersion.toVersion(targetJavaVersion)
     sourceCompatibility = javaVersion