Bump checker-qual from 3.18.0 to 3.18.1
Bump checker-qual from 3.18.0 to 3.18.1

Bumps [checker-qual](https://github.com/typetools/checker-framework) from 3.18.0 to 3.18.1.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a href="https://github.com/typetools/checker-framework/releases">checker-qual's releases</a>.</em></p>
<blockquote>
<h2>Checker Framework 3.18.1</h2>
<h2>Version 3.18.1 (October 4, 2021)</h2>
<p><strong>Closed issues:</strong>
<a href="https://github-redirect.dependabot.com/typetools/checker-framework/issues/4902">#4902</a> and <a href="https://github-redirect.dependabot.com/typetools/checker-framework/issues/4903">#4903</a>.</p>
</blockquote>
</details>
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/typetools/checker-framework/blob/master/docs/CHANGELOG.md">checker-qual's changelog</a>.</em></p>
<blockquote>
<h2>Version 3.18.1 (October 4, 2021)</h2>
<p><strong>Closed issues:</strong>
<a href="https://github-redirect.dependabot.com/typetools/checker-framework/issues/4902">#4902</a> and <a href="https://github-redirect.dependabot.com/typetools/checker-framework/issues/4903">#4903</a>.</p>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/typetools/checker-framework/commit/8d710a9f27e1ed88539b3fd482496245a514cf5a"><code>8d710a9</code></a> new release 3.18.1</li>
<li><a href="https://github.com/typetools/checker-framework/commit/2ef9feab774428e6639d4896c4badd59e2086d8f"><code>2ef9fea</code></a> Update for relesase.</li>
<li><a href="https://github.com/typetools/checker-framework/commit/88f24fc34a3bb55732c50e25a9f86da2ca36a051"><code>88f24fc</code></a> Fix classpath for inference test</li>
<li><a href="https://github.com/typetools/checker-framework/commit/902376d11bbe73a1c4ad000d7771047241517b34"><code>902376d</code></a> Document base directory for classpathExtra</li>
<li><a href="https://github.com/typetools/checker-framework/commit/5ab873175596b026b178465df29269683bcc3e11"><code>5ab8731</code></a> Typo fix</li>
<li><a href="https://github.com/typetools/checker-framework/commit/259ed0e1abbf160495b538a92b3cde102027f417"><code>259ed0e</code></a> Bump classgraph from 4.8.116 to 4.8.117</li>
<li><a href="https://github.com/typetools/checker-framework/commit/cfb37e1d31acfe673d1fd398f57294ea71520dbb"><code>cfb37e1</code></a> Mention the issue tracker</li>
<li><a href="https://github.com/typetools/checker-framework/commit/22ff13cd8915b4d19b226ecdf64d070923a224b4"><code>22ff13c</code></a> Update URL</li>
<li><a href="https://github.com/typetools/checker-framework/commit/854632da39136ffbd26e1193241681c5c010162d"><code>854632d</code></a> Bump error_prone_core from 2.8.1 to 2.9.0</li>
<li><a href="https://github.com/typetools/checker-framework/commit/1eec388c6447de72c056f28b2a6d5a3e7305af61"><code>1eec388</code></a> Update FAQ about RUNTIME vs CLASS retention</li>
<li>Additional commits viewable in <a href="https://github.com/typetools/checker-framework/compare/checker-framework-3.18.0...checker-framework-3.18.1">compare view</a></li>
</ul>
</details>
<br />

[![Dependabot compatibility score](https://dependabot-badges.githubapp.com/badges/compatibility_score?dependency-name=org.checkerframework:checker-qual&package-manager=maven&previous-version=3.18.0&new-version=3.18.1)](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>

Fixes #274

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/compile-testing/pull/274 from google:dependabot/maven/org.checkerframework-checker-qual-3.18.1 d2794b2b0203ecbb6a618a92ed728519b39789f4
PiperOrigin-RevId: 400981292

google/compile-testing