chore(dependencies): Upgrade TS to 4.3.5

TS 4.4.2 is unfortunately not possible yet, as there’s this rollup+typescript bug that will most likely be fixed in TS 4.4.3:

rollup/plugins#983
microsoft/TypeScript#45633

package.json

@@ -47,7 +47,7 @@
 		}
 	],
 	"dependencies": {
-		"typescript": "^3.9.6"
+		"typescript": "4.3"
 	},
 	"devDependencies": {
 		"@babel/core": "7.x",

yarn.lock

@@ -19153,12 +19153,7 @@ typedarray@^0.0.6:
   resolved "https://registry.yarnpkg.com/typedarray/-/typedarray-0.0.6.tgz#867ac74e3864187b1d3d47d996a78ec5c8830777"
   integrity sha1-hnrHTjhkGHsdPUfZlqeOxciDB3c=
 
-typescript@^3.9.6:
-  version "3.9.6"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.6.tgz#8f3e0198a34c3ae17091b35571d3afd31999365a"
-  integrity sha512-Pspx3oKAPJtjNwE92YS05HQoY7z2SFyOpHo9MqJor3BXAGNaPUs83CuVp9VISFkSjyRfiTpmKuAYGJB7S7hOxw==
-
-typescript@^4.3.5:
+typescript@4.3, typescript@^4.3.5:
   version "4.3.5"
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.3.5.tgz#4d1c37cc16e893973c45a06886b7113234f119f4"
   integrity sha512-DqQgihaQ9cUrskJo9kIyW/+g0Vxsk8cDtZ52a3NGh0YNTfpUSArXSohyUGnvbPazEPLu398C0UxmKSOrPumUzA==