chore(ci,docs): archive eest.ethereum.org and stop docs redeploys (#2323)

`eest.ethereum.org` is being archived in favor of the unified docs at
https://steel.ethereum.foundation/docs/execution-specs/. Remove the
`mike` deploy workflow so a push to `main` or a version tag can no longer
rebuild and overwrite the static archive tombstone on `gh-pages`, and note
the docs-site redirect in the README.

Author: danceratopz

.github/workflows/docs_deploy.yaml

@@ -8,6 +8,7 @@ As such, this repository is no longer accepting pull requests as of 2025-11-01.
 - **Test Contributors:**
     - Please direct PRs to [ethereum/execution-specs](https://github.com/ethereum/execution-specs).
     - Read more about the changes effecting test development in our [blog announcement](https://steel.ethereum.foundation/blog/2025-11-04_weld_final/).
+- **Documentation:** [eest.ethereum.org](https://eest.ethereum.org) is archived and now redirects to its new home at [steel.ethereum.foundation/docs/execution-specs](https://steel.ethereum.foundation/docs/execution-specs/).
 
 ### Questions or Feedback About the Migration?