Bump the test group with 2 updates

Bumps the test group with 2 updates: [@axe-core/puppeteer](https://github.com/dequelabs/axe-core-npm) and [puppeteer](https://github.com/puppeteer/puppeteer).


Updates `@axe-core/puppeteer` from 4.8.3 to 4.8.4
- [Release notes](https://github.com/dequelabs/axe-core-npm/releases)
- [Changelog](https://github.com/dequelabs/axe-core-npm/blob/develop/CHANGELOG.md)
- [Commits](dequelabs/axe-core-npm@v4.8.3...4.8.4)

Updates `puppeteer` from 21.7.0 to 21.9.0
- [Release notes](https://github.com/puppeteer/puppeteer/releases)
- [Changelog](https://github.com/puppeteer/puppeteer/blob/main/release-please-config.json)
- [Commits](puppeteer/puppeteer@puppeteer-v21.7.0...puppeteer-v21.9.0)

---
updated-dependencies:
- dependency-name: "@axe-core/puppeteer"
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: test
- dependency-name: puppeteer
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: test
...

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

package.json

@@ -40,7 +40,7 @@
     "lunr": "^2.3.9"
   },
   "devDependencies": {
-    "@axe-core/puppeteer": "^4.8.3",
+    "@axe-core/puppeteer": "^4.8.4",
     "@babel/core": "^7.23.7",
     "@babel/preset-env": "^7.23.8",
     "@metalsmith/in-place": "^5.0.0",
@@ -91,7 +91,7 @@
     "postcss-markdown": "^1.2.0",
     "postcss-scss": "^4.0.9",
     "prettier": "^3.2.4",
-    "puppeteer": "^21.7.0",
+    "puppeteer": "^21.9.0",
     "rollup": "^4.9.6",
     "sass-export": "^2.1.2",
     "serve-static": "^1.15.0",