chore: raise engines.node to >=22

For highlight.js **v12**.

Today `engines.node` is `>=20` (v11 support floor) and we use **commander 14** (CJS, Node `>=20`).

Once we cut v12, bump `engines.node` to `>=22` (current LTS / CI). That also unblocks **commander 15** (ESM-only, Node `>=22.12`) if we still want #4472.

Do not change this on the 11.x line.

Find where the package declares `engines.node` and read the surrounding release configuration; the issue says this change is for v12, not the 11.x line. Done means the v12 line requires Node.js >=22 while the 11.x line remains unchanged.

Written by the indexing model from the issue text.