Bump typescript from 3.5.3 to 3.8.3

Bumps [typescript](https://github.com/Microsoft/TypeScript) from 3.5.3 to 3.8.3.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](microsoft/TypeScript@v3.5.3...v3.8.3)

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

Author: dependabot-preview[bot]

package-lock.json

@@ -65,7 +65,7 @@
     "rewire": "~4.0.1",
     "sinon": "~9.0.1",
     "tslint": "~6.0.0",
-    "typescript": "~3.5.3",
+    "typescript": "~3.8.3",
     "vsce": "~1.74.0",
     "vscode-test": "~1.3.0"
   },