fix: adapt to WorkManager 2.9 Configuration.Provider property

WorkManager 2.9 replaced the getWorkManagerConfiguration() method with a
workManagerConfiguration property on Configuration.Provider.

Author: hawkff

app/src/main/java/io/nekohasekai/sagernet/SagerNet.kt

@@ -109,11 +109,10 @@ class SagerNet : Application(),
         updateNotificationChannels()
     }
 
-    override fun getWorkManagerConfiguration(): WorkConfiguration {
-        return WorkConfiguration.Builder()
+    override val workManagerConfiguration: WorkConfiguration
+        get() = WorkConfiguration.Builder()
             .setDefaultProcessName("${BuildConfig.APPLICATION_ID}:bg")
             .build()
-    }
 
     override fun onTrimMemory(level: Int) {
         super.onTrimMemory(level)