store migration was run for subnet volume

Author: camfairchild

pallets/subtensor/src/migrations/migrate_subnet_volume.rs

@@ -6,7 +6,7 @@ pub fn migrate_subnet_volume<T: Config>() -> Weight {
     let migration_name = b"migrate_subnet_volume".to_vec();
 
     // Initialize the weight with one read operation.
-    let weight = T::DbWeight::get().reads(1);
+    let mut weight = T::DbWeight::get().reads(1);
 
     // Check if the migration has already run
     if HasMigrationRun::<T>::get(&migration_name) {
@@ -29,5 +29,11 @@ pub fn migrate_subnet_volume<T: Config>() -> Weight {
     });
 
     log::info!("Migrated {} entries in SubnetVolume", migrated);
-    weight.saturating_add(T::DbWeight::get().reads_writes(migrated, migrated))
+    weight = weight.saturating_add(T::DbWeight::get().reads_writes(migrated, migrated));
+
+    // Mark the migration as completed
+    HasMigrationRun::<T>::insert(&migration_name, true);
+    weight = weight.saturating_add(T::DbWeight::get().writes(1));
+
+    weight
 }