Fix missing import after #1705 (#1731)

* Fix missing import after #1705; probably was there before I requested changes

Author: eoghanmurray

.changeset/lucky-trainers-joke.md

@@ -2,4 +2,4 @@
 "rrweb-snapshot": patch
 ---
 
-use ownerNode.baseURI for stringifying sheet hrefs
+Use ownerNode.baseURI for stringifying sheet hrefs

.changeset/spotty-emus-listen.md

@@ -0,0 +1,5 @@
+---
+"rrweb-snapshot": patch
+---
+
+Fix missing import after #1705

packages/rrweb-snapshot/test/utils.test.ts

@@ -7,6 +7,7 @@ import {
   extractFileExtension,
   fixSafariColons,
   isNodeMetaEqual,
+  stringifyStylesheet,
 } from '../src/utils';
 import { NodeType } from '@rrweb/types';
 import type { serializedNode, serializedNodeWithId } from '@rrweb/types';