chore(deps): update dependency sphinx-rtd-theme to >=3,<3.2 (#619)

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[sphinx-rtd-theme](https://redirect.github.com/readthedocs/sphinx_rtd_theme)
| `>=3,<3.1` → `>=3,<3.2` |
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setup.py

@@ -41,7 +41,7 @@
     extras_require={
         "docs": [
             "sphinx>=8,<8.3",
-            "sphinx-rtd-theme>=3,<3.1",
+            "sphinx-rtd-theme>=3,<3.2",
             "myst-parser>=5,<5.1",
             "watchdog>=6,<6.1",
         ],