Clarifying the new Load npm builtin configs failed warning

[stefan-toubia]

I'm reviewing the latest release and was hoping to clarify this new warning:

 WARN  Load npm builtin configs failed, you can use "pnpm config ls" to show builtin configs. And then use "pnpm config --global set <key> <value>" to migrate configs from builtin to global.

I'm really not sure what failed, what are the effects of that failure and what part of my config I'm supposed to move over to the global config.

Also, I did try setting one global config setting per the warning message, but got an additional warning:

$ pnpm config --global set cache-dir /Users/stoubia/Library/Caches/pnpm/cache
npm WARN config global `--global`, `--local` are deprecated. Use `--location=global` instead.

[lvqq]

Related: #5518