[BUG] `npm ls` reports missing optional peer deps as missing deps

[isaacs]

Current Behavior:

Missing optional peer deps are reported as problems, even though npm does not install them by default.

Expected Behavior:

Since these are all optional peer deps, they should not be reported as problems.

Steps To Reproduce:

In the cli project right now:

npm run resetdeps
npm prune
npm ls -a

Prints the following warnings:

npm ERR! code ELSPROBLEMS
npm ERR! missing: flow-remove-types@>=2.112.0, required by tap@15.0.4
npm ERR! missing: ts-node@>=8.5.2, required by tap@15.0.4
npm ERR! missing: typescript@>=3.7.2, required by tap@15.0.4
npm ERR! missing: bufferutil@^4.0.1, required by ws@7.4.5
npm ERR! missing: utf-8-validate@^5.0.2, required by ws@7.4.5

Environment:

npm 7.10.0