Fix oauth2 client again

[mattzcarey]

removes the bug where the client was trying to reconnect and start a new auth flow after auth was successful.

showed up with this error:

Error: Failed to authenticate: the client isn't in the `authenticating` state
    at MCPClientManager.handleCallbackRequest (assets/worker-entry-CEsYH8jC.js:32900:83)
    at assets/worker-entry-CEsYH8jC.js:34508:41
    at async Playground.fetch (assets/worker-entry-CEsYH8jC.js:34033:16)

[changeset-bot]

🦋 Changeset detected

Latest commit: 594774d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
agents	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/cloudflare/agents@592

commit: 594774d