Bump markdown-it-anchor from 8.4.1 to 8.6.7

Bumps [markdown-it-anchor](https://github.com/valeriangalliat/markdown-it-anchor) from 8.4.1 to 8.6.7.
- [Release notes](https://github.com/valeriangalliat/markdown-it-anchor/releases)
- [Changelog](https://github.com/valeriangalliat/markdown-it-anchor/blob/master/CHANGELOG.md)
- [Commits](valeriangalliat/markdown-it-anchor@v8.4.1...v8.6.7)

---
updated-dependencies:
- dependency-name: markdown-it-anchor
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

package.json

@@ -40,7 +40,7 @@
     "js-yaml": "^4.1.0",
     "luxon": "^2.3.1",
     "markdown-it": "^12.3.2",
-    "markdown-it-anchor": "^8.4.1",
+    "markdown-it-anchor": "^8.6.7",
     "netlify-cms-proxy-server": "^1.3.23",
     "npm-run-all": "^4.1.5",
     "pa11y-ci": "^3.0.1",