chore(deps-dev): bump mocha from 7.2.0 to 8.1.0

Bumps [mocha](https://github.com/mochajs/mocha) from 7.2.0 to 8.1.0.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](mochajs/mocha@v7.2.0...v8.1.0)

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

package.json

@@ -30,7 +30,7 @@
     "chai": "^4.2.0",
     "eslint": "^6.1.0",
     "eslint-config-hexo": "^4.0.0",
-    "mocha": "^7.1.1",
+    "mocha": "^8.1.0",
     "nyc": "^15.0.0"
   },
   "engines": {