refactor(core): don't use Result in ExtensionBuilder::state (#18066)

There's no point for this API to expect result. If something fails it should
result in a panic during build time to signal to embedder that setup is
wrong.

ext/web/lib.rs

@@ -121,7 +121,6 @@ pub fn init<P: TimersPermission + 'static>(
         state.put(Location(location));
       }
       state.put(StartTime::now());
-      Ok(())
     })
     .build()
 }