Bump eslint from 9.9.0 to 9.9.1 in /webapp (#3966)

Bumps [eslint](https://github.com/eslint/eslint) from 9.9.0 to 9.9.1.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/main/CHANGELOG.md)
- [Commits](eslint/eslint@v9.9.0...v9.9.1)

---
updated-dependencies:
- dependency-name: eslint
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

webapp/package.json

@@ -34,7 +34,7 @@
     "@eslint/js": "^9.5.0",
     "@polymer/test-fixture": "4.0.2",
     "cpy-cli": "5.0.0",
-    "eslint": "9.9.0",
+    "eslint": "9.9.1",
     "eslint-plugin-html": "8.1.1",
     "globals": "^15.9.0",
     "wct-browser-legacy": "1.0.2",