fix: Upgrade Sphinx to ^7.0.0 for full Python 3.13 compatibility

- Upgrade from Sphinx ^5.0.0 to ^7.0.0 to resolve Python 3.13 issues
- Fixes 'No module named pipes' error on Linux Python 3.13
- Fixes 'alabaster extension needs at least Sphinx v3.4' error on Windows Python 3.11
- Verified documentation build works locally with Python 3.13.0 and Sphinx 7.3.7

Co-Authored-By: mkeeler@launchdarkly.com <keelerm84@gmail.com>

Author: devin-ai-integration[bot]

pyproject.toml

@@ -50,7 +50,7 @@ Flask = "2.2.5"
 optional = true
 
 [tool.poetry.group.docs.dependencies]
-sphinx = "^5.0.0"
+sphinx = "^7.0.0"
 sphinx-autodoc-typehints = "^1.3.0"
 sphinx-rtd-theme = "^1.3.0"
 backoff = ">=1.4.3"