Update the workerd compatibility date (#79)

Moves the compatibility date further forward so that the tests can pick up newer stuff like `Headers` `getSetCookie()`

Co-authored-by: Matt Kane <[email protected]>

generator/runtimes/workerd/config.capnp

@@ -30,7 +30,7 @@ const helloWorld :Workerd.Worker = (
  modules = [
  (name = "worker", esModule = embed "dist/handler.mjs")
  ],
- compatibilityDate = "2023-02-28",
+ compatibilityDate = "2024-03-01",
  compatibilityFlags = ["nodejs_compat", "experimental"],
  bindings = [
  (name = "unsafe", unsafeEval = void )