Bump typescript from 3.9.7 to 4.0.2

Bumps [typescript](https://github.com/Microsoft/TypeScript) from 3.9.7 to 4.0.2.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](microsoft/TypeScript@v3.9.7...v4.0.2)

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

Author: dependabot-preview[bot]

package-lock.json

@@ -48,7 +48,7 @@
     "rollup-plugin-typescript2": "^0.27.2",
     "tslib": "^2.0.1",
     "typedoc": "^0.18.0",
-    "typescript": "^3.8.3"
+    "typescript": "^4.0.2"
   },
   "browserslist": [
     "extends @nextcloud/browserslist-config"