⬆️ Bump js-yaml from 3.14.1 to 4.0.0

Bumps [js-yaml](https://github.com/nodeca/js-yaml) from 3.14.1 to 4.0.0.
- [Release notes](https://github.com/nodeca/js-yaml/releases)
- [Changelog](https://github.com/nodeca/js-yaml/blob/master/CHANGELOG.md)
- [Commits](nodeca/js-yaml@3.14.1...4.0.0)

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

package.json

@@ -37,7 +37,7 @@
     "@octokit/rest": "^18.0.3",
     "compression": "^1.7.4",
     "fs-extra": "^9.0.1",
-    "js-yaml": "^3.14.0",
+    "js-yaml": "^4.0.0",
     "polka": "next",
     "sirv": "^1.0.5",
     "snarkdown": "^2.0.0",