eslint.packageManager deprecated but error message says to use it

[tillig]

Based on the readme and this code in client.ts which detects the package manager, it seems the eslint.pacakageManager setting is deprecated.

However, if the ESLint library fails to load for whatever reason, the error message for that case still indicates that we should use eslint.packageManager to fix the issue.

It makes solving the problem somewhat confusing because I'm not sure if I should be setting that or not.