refactor: remove unused code [SyncStatus]

* hasBeenMarkedAsChangedInMemory
* markDataAsChanged
* sPauseCheckingDatabase
* sMarkedInMemory

AnkiDroid/src/main/java/com/ichi2/utils/SyncStatus.kt

@@ -34,8 +34,6 @@ enum class SyncStatus {
     NO_ACCOUNT, NO_CHANGES, HAS_CHANGES, FULL_SYNC, BADGE_DISABLED, ERROR;
 
     companion object {
-        private var sPauseCheckingDatabase = false
-        private var sMarkedInMemory = false
 
         suspend fun getSyncStatus(context: Context, auth: SyncAuth?): SyncStatus {
             if (isDisabled) {
@@ -76,19 +74,5 @@ enum class SyncStatus {
                 val preferences = AnkiDroidApp.sharedPrefs()
                 return !preferences.getBoolean("showSyncStatusBadge", true)
             }
-
-        /** To be converted to Rust  */
-        fun markDataAsChanged() {
-            if (sPauseCheckingDatabase) {
-                return
-            }
-            sMarkedInMemory = true
-            AnkiDroidApp.sharedPrefs().edit { putBoolean("changesSinceLastSync", true) }
-        }
-
-        /** Whether a change in data has been detected - used as a heuristic to stop slow operations  */
-        fun hasBeenMarkedAsChangedInMemory(): Boolean {
-            return sMarkedInMemory
-        }
     }
 }