fix(client): wait on the socket host, not the ping host (#6819)

packages/vite/src/client/client.ts

@@ -201,12 +201,10 @@ async function waitForSuccessfulPing(ms = 1000) {
   // eslint-disable-next-line no-constant-condition
   while (true) {
     try {
-      const pingResponse = await fetch(`${base}__vite_ping`)
-
-      // success - 2xx status code
-      if (pingResponse.ok) break
-      // failure - non-2xx status code
-      else throw new Error()
+      // A fetch on a websocket URL will return a successful promise with status 400,
+      // but will reject a networking error.
+      await fetch(`${location.protocol}//${socketHost}`)
+      break
     } catch (e) {
       // wait ms before attempting to ping again
       await new Promise((resolve) => setTimeout(resolve, ms))