Update Sphinx version to 7.1.2

- Updated the Sphinx version in requirements.txt from 7.2.6 to 7.1.2 for compatibility reasons.
- This change ensures that the project continues to work smoothly with the updated Sphinx version.

doc/requirements.txt

@@ -2,7 +2,7 @@ aiohttp==3.9.1
 aiohttp_apispec==2.2.3
 pydantic==1.10.14
 pygments==2.17.2
-sphinx==7.2.6
+sphinx==7.1.2
 sphinx_rtd_theme==2.0.0
 sphinxcontrib-httpdomain==1.8.1
 sphinxcontrib-openapi==0.8.3