Update ephemeral documentation URLs once 1.11 is out of beta

[Gogotchuri]

We are adding beta documentation URLs for v1.11 ephemeral support (https://opentofu.org/docs/v1.11/language/ephemerality/ephemeral-resources/)
Once OpenTofu v1.11 is out of beta, we should switch the URLs to point at the latest documentation instead.

Originally posted by @yottta in #44 (comment)

[cam72cam]

@Gogotchuri that link is active now and durable.

[Gogotchuri]

@cam72cam My bad, I meant to say update that link, not to the link. I've created an issue from the original comment, but I haven't paid attention.
We need that to refer to the latest version docs after 1.11 is out of beta.