Update TypeScript to v4.2

TypeScript has been updated to v4.2 [1]. I'm not aware of any changes
that impact our code.

TypeScript v4.2 is still not supported by
`@typescript-eslint/eslint-plugin` and `typedoc`, so they give a
warning at runtime and install time respectively.

[1]: https://devblogs.microsoft.com/typescript/announcing-typescript-4-2/

Author: Gudahtt

package.json

@@ -80,7 +80,7 @@
     "sinon": "^9.2.4",
     "ts-jest": "^26.5.2",
     "typedoc": "^0.20.28",
-    "typescript": "~4.1.5"
+    "typescript": "~4.2.2"
   },
   "jest": {
     "moduleFileExtensions": [

yarn.lock

@@ -7047,10 +7047,10 @@ typedoc@^0.20.28:
     shiki "^0.9.2"
     typedoc-default-themes "^0.12.7"
 
-typescript@~4.1.5:
-  version "4.1.5"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.1.5.tgz#123a3b214aaff3be32926f0d8f1f6e704eb89a72"
-  integrity sha512-6OSu9PTIzmn9TCDiovULTnET6BgXtDYL4Gg4szY+cGsc3JP1dQL8qvE8kShTRx1NIw4Q9IBHlwODjkjWEtMUyA==
+typescript@~4.2.2:
+  version "4.2.2"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.2.2.tgz#1450f020618f872db0ea17317d16d8da8ddb8c4c"
+  integrity sha512-tbb+NVrLfnsJy3M59lsDgrzWIflR4d4TIUjz+heUnHZwdF7YsrMTKoRERiIvI2lvBG95dfpLxB21WZhys1bgaQ==
 
 uglify-js@^3.1.4:
   version "3.6.5"