chore(deps-dev): bump @types/serverless from 3.12.18 to 3.12.20 (#158)

Bumps [@types/serverless](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/serverless) from 3.12.18 to 3.12.20.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/serverless)

---
updated-dependencies:
- dependency-name: "@types/serverless"
  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>

package.json

@@ -46,7 +46,7 @@
     "@types/chai-as-promised": "^7.1.8",
     "@types/mocha": "^10.0.6",
     "@types/node": "^20.10.6",
-    "@types/serverless": "^3.12.18",
+    "@types/serverless": "^3.12.20",
     "@typescript-eslint/eslint-plugin": "^6.16.0",
     "@typescript-eslint/parser": "^6.16.0",
     "c8": "^8.0.1",