tsconfig: Use ESNext in target and lib

From what I can tell, the value of target doesn't actually matter,
because we have noEmit set to true - its esbuild in dev (configured
by Vite's esbuild.target) and Rollup for prod build (configured by
build.target) that do the transpiling, but there's no harm in
updating it anyway.

Setting "lib" to include ESNext allows us to use more modern features
such as "promise.any, string.replaceAll etc" (ES2021) and
"array.at, RegExp.hasIndices, etc." (ES2022).

Its also worth noting that these are the values of the tsconfig.json
that come when using Laravel Breeze with one of its TS starters.

See:
* https://www.typescriptlang.org/tsconfig#lib
* https://www.typescriptlang.org/tsconfig#target
* https://github.com/laravel/breeze/blob/095c4c597c3719e2a596fcf4689288e9cdbc6520/stubs/inertia-react-ts/tsconfig.json

tsconfig.json

@@ -1,9 +1,9 @@
 {
   "compilerOptions": {
-    "target": "ES2020",
+    "target": "ESNext",
     "useDefineForClassFields": true,
     "module": "ESNext",
-    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "lib": ["ESNext", "DOM", "DOM.Iterable"],
     "skipLibCheck": true,
 
     /* Bundler mode */