ENOENT value reset fix and version bumps

[maybephilipp]

Hey there!

Dear Walking Pizza, I'm raising a PR to address few issues I had while using the plugin in my project:

1. Plugin raises a huge bunch of errors in console when using strapi import command with --only content,config option (obviously, because assets are missing yet)
2. Plugin sets null in case of error even if database/record had a value in the placeholder before. That causes imported dump to have all placeholder set to null.

What I've done:

• Bumped node version (my project depends on v19)
• Bumped eslint and prettier (just because of good will)
• Added babel/eslint-parser (because eslint was blaming ?? operator everywhere)
• Changed error to warning in case of ENOENT exception
• Added condition check to not override existing placeholder in case of ENOENT

Hope you find this PR helpful and worth pushing. Any comments/improvements are appreciated!