fix: bugcollect-plugin Java 17 → 21（Jenkins agent 已有 Java 21）

sdk-bugcollect-plugin/build.gradle.kts

@@ -15,12 +15,12 @@ val pluginVersion: String by lazy {
 version = pluginVersion
 
 java {
-    sourceCompatibility = JavaVersion.VERSION_17
-    targetCompatibility = JavaVersion.VERSION_17
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
 }
 
 kotlin {
-    jvmToolchain(17)
+    jvmToolchain(21)
 }
 
 gradlePlugin {