Bump pkg-up from 3.1.0 to 4.0.0#137

Bumps [pkg-up](https://github.com/sindresorhus/pkg-up) from 3.1.0 to 4.0.0. <details> <summary>Release notes</summary> <p><em>Sourced from <a href="https://github.com/sindresorhus/pkg-up/releases">pkg-up's releases</a>.</em></p> <blockquote> <h2>v4.0.0</h2> <h3>Breaking</h3> <ul> <li>Require Node.js 12.20 1bca773</li> <li>This package is now pure ESM. <strong>Please <a href="https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c">read this</a>.</strong></li> <li><a href="https://github.com/sindresorhus/pkg-up/compare/v3.1.0...v4.0.0#diff-5a831ea67cf5cf8703b0de46901ab25bd191f56b320053be9332d9a3b0d01d15L28-R26">Moved from a default export to named exports.</a></li> <li>It now returns <code>undefined</code> instead of <code>null</code> if a package.json cannot be found.</li> </ul> <p><a href="https://github.com/sindresorhus/pkg-up/compare/v3.1.0...v4.0.0">https://github.com/sindresorhus/pkg-up/compare/v3.1.0...v4.0.0</a></p> </blockquote> </details> <details> <summary>Commits</summary> <ul> <li><a href="https://github.com/sindresorhus/pkg-up/commit/78730d5a721fefbc45c8b4d65bb6679a4fbdcbbb"><code>78730d5</code></a> 4.0.0</li> <li><a href="https://github.com/sindresorhus/pkg-up/commit/1bca773d68d08654311c5416a5f3883d7053b766"><code>1bca773</code></a> Require Node.js 12.20 and move to ESM</li> <li><a href="https://github.com/sindresorhus/pkg-up/commit/aa84553daeca395ef7d5cfce7b09aab4748690bc"><code>aa84553</code></a> Move to GitHub Actions (<a href="https://github-redirect.dependabot.com/sindresorhus/pkg-up/issues/6">#6</a>)</li> <li><a href="https://github.com/sindresorhus/pkg-up/commit/a4bc80ae29b9bc371613018b88fd37b38e9da74f"><code>a4bc80a</code></a> Create funding.yml</li> <li><a href="https://github.com/sindresorhus/pkg-up/commit/cbcc347a4f5438a2f98360b993d5f8211db4dbf7"><code>cbcc347</code></a> Add Node.js 12 to testing (<a href="https://github-redirect.dependabot.com/sindresorhus/pkg-up/issues/5">#5</a>)</li> <li>See full diff in <a href="https://github.com/sindresorhus/pkg-up/compare/v3.1.0...v4.0.0">compare view</a></li> </ul> </details> <br /> [](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores) Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`. [//]: # (dependabot-automerge-start) [//]: # (dependabot-automerge-end) --- <details> <summary>Dependabot commands and options</summary> <br /> You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot merge` will merge this PR after your CI passes on it - `@dependabot squash and merge` will squash and merge this PR after your CI passes on it - `@dependabot cancel merge` will cancel a previously requested merge and block automerging - `@dependabot reopen` will reopen this PR if it is closed - `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself) </details>