Bump @types/mocha from 5.2.7 to 9.0.0 (Azure#15342)

Bumps [@types/mocha](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/mocha) from 5.2.7 to 9.0.0.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/mocha)

---
updated-dependencies:
- dependency-name: "@types/mocha"
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

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

package.json

@@ -15,7 +15,7 @@
     "@ts-common/fs": "0.2.0",
     "@ts-common/iterator": "^0.3.6",
     "@types/js-yaml": "^3.12.1",
-    "@types/mocha": "^5.2.6",
+    "@types/mocha": "^9.0.0",
     "@types/prettier": "^2.3.0",
     "cspell": "^4.0.30",
     "js-yaml": "^3.13.1",