Archive LGPU repo

[mlxd]

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---

Context: This PR adds the archival notice to LGPU, in preparation of of making the repo read-only at v0.32.0.

Description of the Change:

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[github-actions]

Hello. You may have forgotten to update the changelog!
Please edit .github/CHANGELOG.md with:

• A one-to-two sentence description of the change. You may include a small working example for new features.
• A link back to this PR.
• Your name (or GitHub username) in the contributors section.

[trbromley]

Thanks! Will the warning show up in the docs too?

[mlxd]

Thanks! Will the warning show up in the docs too?

If the docs build succeeds, it will show up in latest. Will try to fix the failure, as not much info is given.

[maliasadi]

Thanks @mlxd!

[vincentmr]

Looks good to me.

[maliasadi]

LGTM 🦣