Don't use experimental decorators in extensions

Seeing if we can compile our extensions using TS native which doesn't support these. The usage is so low that I think we can just remove them

extensions/typescript-language-features/tsconfig.json

@@ -3,7 +3,6 @@
 	"compilerOptions": {
 		"outDir": "./out",
 		"esModuleInterop": true,
-		"experimentalDecorators": true,
 		"types": [
 			"node"
 		]