Remove dependency on sphinx-autodoc-typehints (Qiskit/qiskit-metapack…

…age#1716)

Since Sphinx 5, this has had first-party support.  This removes a docs
dependency that has caused us significant problems before due to its
instability, and the built-in handling in `autodoc` is much cleaner as
well.  This commit is a mirror of Terra commit dfcfa4a.

docs/conf.py

@@ -53,7 +53,6 @@
     'sphinx.ext.mathjax',
     'sphinx.ext.viewcode',
     'sphinx.ext.extlinks',
-    'sphinx_autodoc_typehints',
     'jupyter_sphinx',
     'nbsphinx',
     'sphinx_design',
@@ -161,6 +160,13 @@
 autosummary_generate_overwrite = False
 autoclass_content = 'both'
 
+# Move type hints from signatures to the parameter descriptions (except in overload cases, where
+# that's not possible).
+autodoc_typehints = "description"
+# Only add type hints from signature to description body if the parameter has documentation.  The
+# return type is always added to the description (if in the signature).
+autodoc_typehints_description_target = "documented_params"
+
 # Plot directive configuration
 # ----------------------------