Build(deps): Bump pypa/gh-action-pypi-publish from 1.7.1 to 1.8.1 (#513)

Bumps [pypa/gh-action-pypi-publish](https://github.com/pypa/gh-action-pypi-publish) from 1.7.1 to 1.8.1.
- [Release notes](https://github.com/pypa/gh-action-pypi-publish/releases)
- [Commits](pypa/gh-action-pypi-publish@v1.7.1...v1.8.1)

---
updated-dependencies:
- dependency-name: pypa/gh-action-pypi-publish
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/main.yml

@@ -140,7 +140,7 @@ jobs:
       run: |
         pandoc -s -o README.md README.rst
     - name: PyPI upload
-      uses: pypa/gh-action-pypi-publish@v1.7.1
+      uses: pypa/gh-action-pypi-publish@v1.8.1
       with:
         packages_dir: dist
         password: ${{ secrets.PYPI_API_TOKEN }}