bump required node version to v14

[axe312ger]

@axe312ger Thanks for the reply and your quick release. Unfortunately it did not help.

To answer your first question: Yes there is a node_modules/sqip-plugin-primitive/package.json with a valid main entry point. But I think I found the issue. It's due to node version v12.22.3 we are using. Package 'fs/promises' is not available in this version and the plugin fails to load.

I found some comments about it, pretty weird: 'fs/promises' was being introduced in Node 10 but then removed in later patches for Node 10 and Node 12. Works fine in Node 14. Node.js documentation was incorrectly listing this as supported in Node 12 (nodejs/node#35740).

So I guess we have to tell our hoster, that we need a node version bump.

Originally posted by @rrutsche in #221 (comment)