fix(docs): remove sphinx-autodoc-typehints to fix CI build failure

The extension injects :rtype: fields after the Examples section,
causing docutils to emit an "unexpected unindent" warning for methods
with Iterator return types + code-block examples (e.g. GrpcIndex.list).
sphinx.ext.autodoc's built-in autodoc_typehints="description" support
covers the same use case without the conflict.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

Author: jhamon

docs/conf.py

@@ -16,7 +16,6 @@
     "sphinx.ext.intersphinx",
     "sphinx.ext.doctest",
     "sphinx.ext.coverage",
-    "sphinx_autodoc_typehints",
     "sphinx_copybutton",
     "sphinx_tabs.tabs",
     "myst_parser",

pyproject.toml

@@ -52,7 +52,6 @@ docs = [
     "sphinx>=8.0",
     "furo",
     "myst-parser>=4.0",
-    "sphinx-autodoc-typehints>=2.0",
     "sphinx-copybutton",
     "sphinx-tabs",
 ]