Bump yarl from 1.7.2 to 1.8.1 (#626)

Bumps [yarl](https://github.com/aio-libs/yarl) from 1.7.2 to 1.8.1.
- [Release notes](https://github.com/aio-libs/yarl/releases)
- [Changelog](https://github.com/aio-libs/yarl/blob/master/CHANGES.rst)
- [Commits](https://github.com/aio-libs/yarl/compare/v1.7.2...v1.8.1)

---
updated-dependencies:
- dependency-name: yarl
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -32,7 +32,7 @@ typing-extensions==4.3.0
 webencodings==0.5.1
 xhtml2pdf==0.2.8
 XMind==1.2.0
-yarl==1.7.2
+yarl==1.8.1
 networkx==2.5.1
 pyvis==0.2.1
 reportlab==3.6.11