Fix (Icon List): add use tag on kses

[kaeizen]

No description provided.

[github-actions]

🤖 Pull request artifacts

file	commit
pr3323-stackable-3323-merge.zip	5792a18

[github-actions]

Try this Pull Request in the WordPress playground: https://playground.wordpress.net/?mode=seamless#{"landingPage":"/wp-admin/post-new.php?post_type=page","preferredVersions":{"php":"latest","wp":"latest"},"steps":[{"step":"login","username":"admin","password":"password"},{"step":"installPlugin","pluginZipFile":{"resource":"url","url":"https://raw.githubusercontent.com/gambitph/Stackable/artifacts/pr3323-stackable-3323-merge.zip"}}]}

[andeng1106]

Note only:
Steps taken before fix:

1. Log in as contributor
2. Add a new post
3. Add an Icon List
4. Save page
5. Log in as admin
6. See post from step 2
7. See block errors