chore(deps-dev): bump xenon from 0.7.3 to 0.8.0 (#669)

Bumps [xenon](https://github.com/rubik/xenon) from 0.7.3 to 0.8.0.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/rubik/xenon/blob/master/CHANGELOG">xenon's changelog</a>.</em></p>
<blockquote>
<h2>0.8.0 (Sep 03, 2021)</h2>
<ul>
<li>Widen requirements to allow Radon v5: <a href="https://github-redirect.dependabot.com/rubik/xenon/issues/43">#43</a>, thanks to <a href="https://github.com/dsch"><code>@​dsch</code></a></li>
</ul>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/rubik/xenon/commit/af557b2a98d67afec74c58fa9b6a9ebf6f60120a"><code>af557b2</code></a> chore(release): bump to v0.8.0</li>
<li><a href="https://github.com/rubik/xenon/commit/d5baeb5a0ea94b25bfaac6434bba1fcf51dded3b"><code>d5baeb5</code></a> chore: widen required radon version to include 5.x (<a href="https://github-redirect.dependabot.com/rubik/xenon/issues/43">#43</a>)</li>
<li><a href="https://github.com/rubik/xenon/commit/a3667b2962bbdc5c38c2dee601e6e64f2301f01e"><code>a3667b2</code></a> chore: update tox environments</li>
<li>See full diff in <a href="https://github.com/rubik/xenon/compare/v0.7.3...v0.8.0">compare view</a></li>
</ul>
</details>
<br />


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</details>

pyproject.toml

@@ -47,7 +47,7 @@ pdoc3 = "^0.10.0"
 pytest-asyncio = "^0.15.1"
 bandit = "^1.7.0"
 radon = "^4.5.0"
-xenon = "^0.7.3"
+xenon = "^0.8.0"
 flake8-eradicate = "^1.1.0"
 flake8-bugbear = "^21.3.2"
 mkdocs-material = "^7.2.6"