fix: Unnecessary variables and ESLint errors

[Ivan12273]

Hi, while I was reading the code I found that there are variables that are never used:

In the file ls.js the function getChildren do a filter by the selected workspaces an other by edges types if shouldSkipChildren is false.

The function "filterByEdgesTypes" filter debs by type and allows for: npm ls [--dev, --prod, --link, etc.]

But the variables node and tree are never used by this function.

Also, the npx-cli.js file have problems related to ESLint style.

In order to prevent future errors and have a more clear code, if there is no problem, I will submit a pull request with the changes I did :)