Remove SaveChangesAsync from IRepository interface

The `SaveChangesAsync` method was removed from the `IRepository`
interface in the `ECMJobRunner.Domain.Interfaces` namespace.
This method previously allowed saving all changes asynchronously
with an optional `CancellationToken` parameter.

ECMJobRunner.Domain/Interfaces/IRepository.cs

@@ -90,10 +90,5 @@ namespace ECMJobRunner.Domain.Interfaces
         /// <param name="cancellationToken">Cancellation token</param>
         /// <returns>True if entity was found and deleted, false otherwise</returns>
         Task<bool> DeleteSingleAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken = default);
-
-        /// <summary>
-        /// Save all changes asynchronously
-        /// </summary>
-        Task<int> SaveChangesAsync(CancellationToken cancellationToken = default);
     }
 }