chore: add knip to validate included dependencies

[voxpelli]

Requirements

• Filling out the template is required. Any pull request that does not include enough information to be reviewed in a timely manner may be closed at the maintainers' discretion.
• All new code requires tests to ensure against regressions.

Description of the Change

Alternate Designs

Why should this be in core?

Benefits

Possible Drawbacks

Applicable issues

[voxpelli]

Thoughts:

• Split out the nps removal from this PR into its own: 🛠 Repo: Replace nps with ordinary npm scripts #5126
• Split out the husky update / replacement / removal into its own PR: 🛠 Repo: Remove husky for now #5124
• Instead of validate-conventional-commit use https://github.com/mtfoley/pr-compliance-action + squash merge: chore: add mtfoley/pr-compliance-action #5077

That leaves this PR doing only knip, which is good, and we can rebase it until it passes and when it passes we can merge it 🎉

[voxpelli]

Still eg. complains on:

@11ty/eleventy         package.json
@mocha/docdash         package.json
assetgraph-builder     package.json
autoprefixer           package.json
canvas                 package.json
coffeescript           package.json
coveralls              package.json
eslint-plugin-node     package.json
husky                  package.json
hyperlink              package.json
jsdoc                  package.json
jsdoc-ts-utils         package.json
karma-chrome-launcher  package.json
karma-sauce-launcher   package.json
markdown-toc           package.json
needle                 package.json
nyc                    package.json
strip-ansi             package.json
svgo                   package.json
update-notifier        package.json
webpack-cli            package.json

[voxpelli]

This is ready now as well, after the merge of #5128

[coveralls]

coverage: 94.495% (-0.002%) from 94.497%
when pulling 150c5c9 on voxpelli/issue5041
into c44653a on main.

[JoshuaKGoldberg]

💯 let's ship it!