build(deps-dev): bump eslint-plugin-mozilla in /frontend (#751)

Bumps [eslint-plugin-mozilla](http://firefox-source-docs.mozilla.org/tools/lint/linters/eslint-plugin-mozilla.html) from 2.9.1 to 2.9.2.

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

frontend/package-lock.json

@@ -34,7 +34,7 @@
     "eslint-loader": "^4.0.0",
     "eslint-plugin-fetch-options": "0.0.5",
     "eslint-plugin-html": "^6.0.0",
-    "eslint-plugin-mozilla": "^2.1.0",
+    "eslint-plugin-mozilla": "^2.9.2",
     "eslint-plugin-no-unsanitized": "^3.0.2",
     "eslint-plugin-prettier": "^3.1.0",
     "file-loader": "^6.0.0",