Bump typescript from 4.1.2 to 4.6.4 in /functions

Bumps [typescript](https://github.com/Microsoft/TypeScript) from 4.1.2 to 4.6.4.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](microsoft/TypeScript@v4.1.2...v4.6.4)

---
updated-dependencies:
- dependency-name: typescript
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

functions/package-lock.json

@@ -33,7 +33,7 @@
     "mocha": "^8.2.1",
     "ts-node": "^9.1.1",
     "tslint": "^6.1.3",
-    "typescript": "^4.1.2"
+    "typescript": "^4.6.4"
   },
   "private": true
 }