Bump pyxel from 2.0.11 to 2.0.13

Bumps [pyxel](https://github.com/kitao/pyxel) from 2.0.11 to 2.0.13.
- [Release notes](https://github.com/kitao/pyxel/releases)
- [Changelog](https://github.com/kitao/pyxel/blob/main/CHANGELOG.md)
- [Commits](kitao/pyxel@v2.0.11...v2.0.13)

---
updated-dependencies:
- dependency-name: pyxel
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -2,4 +2,4 @@ black==24.4.2
 flake8==7.0.0
 isort==5.13.2
 nox==2024.4.15
-pyxel==2.0.11
+pyxel==2.0.13