[BUG] 1.3.8 patch release dropped support for Node 18 even though it supports ESM

[mdarens]

Describe the bug
The release notes for 1.3.8 indicate migration to ES modules, and also requires Node >= 20 for the engine, even though Node 18 has full support for them, and is in maintenance LTS until mid-2025.

Ideally the ESM release of this package would not be tied to Node 20, but if it has to be, it should be a major version change.