Bump tiptap-extensions from 1.28.4 to 1.28.6

Bumps [tiptap-extensions](https://github.com/scrumpy/tiptap) from 1.28.4 to 1.28.6.
- [Release notes](https://github.com/scrumpy/tiptap/releases)
- [Commits](https://github.com/scrumpy/tiptap/compare/tiptap-extensions@1.28.4...tiptap-extensions@1.28.6)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -38,7 +38,7 @@
 		"nextcloud-vue-collections": "^0.7.1",
 		"tippy.js": "^4.3.5",
 		"tiptap": "^1.26.3",
-		"tiptap-extensions": "^1.28.3",
+		"tiptap-extensions": "^1.28.6",
 		"url-search-params-polyfill": "^7.0.1",
 		"vue": "^2.6.11",
 		"vue-click-outside": "^1.0.7",