⬆️ Dep: Update sphinx requirement from >=5,<6 to >=5,<8

Updates the requirements on [sphinx](https://github.com/sphinx-doc/sphinx) to permit the latest version.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinx@v5.0.0...v7.1.2)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -67,7 +67,7 @@ pytest-loguru = "^0.2.0"
 optional = true
 
 [tool.poetry.group.docs.dependencies]
-sphinx = ">=5,<6"
+sphinx = ">=5,<8"
 sphinx_bootstrap_theme = "^0.8.1"
 sphinxext-remoteliteralinclude = "^0.4.0"