Remove FeatureFlag.SyncOnPush

libraries/featureflag/api/src/main/kotlin/io/element/android/libraries/featureflag/api/FeatureFlags.kt

@@ -34,13 +34,6 @@ enum class FeatureFlags(
         defaultValue = { false },
         isFinished = false,
     ),
-    SyncOnPush(
-        key = "feature.syncOnPush",
-        title = "Sync on push",
-        description = "Subscribe to room sync when a push is received",
-        defaultValue = { true },
-        isFinished = false,
-    ),
     OnlySignedDeviceIsolationMode(
         key = "feature.onlySignedDeviceIsolationMode",
         title = "Exclude insecure devices when sending/receiving messages",