Update mathtools tag example

Author: dpvc

testsuite/package.json

@@ -14,7 +14,7 @@
   },
   "dependencies": {
     "@jest/globals": "^29.7.0",
-    "@mathjax/mathjax-bbm-font-extension": "0.4.2-beta.8",
+    "@mathjax/mathjax-bbm-font-extension": "^4.0.0",
     "@types/jest": "^29.5.14",
     "jest": "^29.7.0",
     "ts-jest": "^29.3.4",

testsuite/tests/input/tex/Mathtools.test.ts

@@ -6176,7 +6176,7 @@ describe('Mathtools options', () => {
 
   test('non-ams tags', () => {
     class myTags extends AbstractTags {
-      formatTag(tag: string) {return `[[${tag}]]`}
+      formatTag(tag: string) {return ['[[', tag, ']]']}
     };
     Configuration.create('mytags', {
       [ConfigurationType.TAGS]: {mytags: myTags},