Add missing await to unified list test operations. (#577)

Add missing await to unified list test operations.

Author: DmitryLukyanov

tests/MongoDB.Driver.Tests/UnifiedTestOperations/UnifiedListCollectionsOperation.cs

@@ -63,7 +63,7 @@ public async Task<OperationResult> ExecuteAsync(CancellationToken cancellationTo
                     ? await _database.ListCollectionsAsync(_options, cancellationToken)
                     : await _database.ListCollectionsAsync(_session, _options, cancellationToken);
 
-                _ = cursor.ToListAsync(cancellationToken);
+                _ = await cursor.ToListAsync(cancellationToken);
 
                 return OperationResult.Empty();
             }

tests/MongoDB.Driver.Tests/UnifiedTestOperations/UnifiedListIndexesOperation.cs

@@ -63,7 +63,7 @@ public async Task<OperationResult> ExecuteAsync(CancellationToken cancellationTo
                     ? await _collection.Indexes.ListAsync(_listIndexesOptions, cancellationToken)
                     : await _collection.Indexes.ListAsync(_session, _listIndexesOptions, cancellationToken);
 
-                _ = cursor.ToListAsync(cancellationToken);
+                _ = await cursor.ToListAsync(cancellationToken);
 
                 return OperationResult.Empty();
             }