chore: add lean4-cli to release checklist

[kim-em]

Users have requested toolchain tags on lean4-cli, so let's add it to the release checklist to make sure these get added regularly.

Previously, lean4-cli has used more complicated tags, but going forward we're going to just use the simple v4.16.0 style tags, with no repository-specific versioning.

[leanprover-community-bot]

Mathlib CI status (docs):

• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase ed309dc2a4cda70f376b98a001dd734a17924d87 --onto dd6445515ddc71826c76b8020fe9e030579b432b. (2025-01-10 09:44:00)
• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase ed309dc2a4cda70f376b98a001dd734a17924d87 --onto d2c4471cfa4611977bf4927b5cd849df1a4272b7. (2025-01-11 00:35:28)