chore(deps): update dependency sphinx to v9

Author: renovate[bot]

pyproject.toml

@@ -189,7 +189,7 @@ dev = [
     "pytest-xdist[psutil]>=3.8.0,<4",
     "ruff>=0.14.8,<1",
     "scalene>=2.0.1,<3",
-    "sphinx>=8.2.3,<9",
+    "sphinx>=9.1,<10",
     "sphinx-autobuild>=2025.8.25,<2026",
     "sphinx-click>=6.2.0,<7",
     "sphinx-copybutton>=0.5.2,<1",