Change to default Licensing (ISC -> Unlicensed/omitted)

People are finding that they are accidentally setting licenses to ISC, then changing them to incompatible licenses later. We should consider this a breaking change, as people depend on it as well. Of note, users do have a way to change the default init-license=MIT to ~/.npmrc

Options:

• omit the field like this: make the license field of npm init more stubborn #655
• change to 'unlicensed': Change default license to UNLICENSED cli#7727

Related: npm/cli#8229

Commentary

omitting is likely the good option here with a link to help users choose.