Remove invite codes from README (bluesky-social#2988)

Invite codes aren't needed anymore!

Thanks to https://bsky.app/profile/shreyanjain.net/post/3kmdulzeibc2o for pointing this out to me.

Author: steveklabnik

README.md

@@ -65,8 +65,6 @@ If you discover any security issues, please send an email to security@bsky.app.
 
 Bluesky is an open social network built on the AT Protocol, a flexible technology that will never lock developers out of the ecosystems that they help build. With atproto, third-party can be as seamless as first-party through custom feeds, federated services, clients, and more.
 
-If you're a developer interested in building on atproto, we'd love to email you a Bluesky invite code. Simply share your GitHub (or similar) profile with us via [this form](https://forms.gle/BF21oxVNZiDjDhXF9).
-
 ## License (MIT)
 
 See [./LICENSE](./LICENSE) for the full license.