Sequence is immutable

Author: fogelito

src/Database/Database.php

@@ -6180,6 +6180,7 @@ public function updateDocument(string $collection, string $id, Document $documen
 
             $document = \array_merge($old->getArrayCopy(), $document->getArrayCopy());
             $document['$collection'] = $old->getAttribute('$collection'); // Make sure user doesn't switch collection ID
+            $document['$sequence'] = $old->getSequence(); // Sequence is immutable
             $document['$createdAt'] = ($createdAt === null || !$this->preserveDates) ? $old->getCreatedAt() : $createdAt;
 
             if ($this->adapter->getSharedTables()) {