Show version in error tracebacks

[kdeldycke]

Add the extension version to the plugin metadata so Sphinx can report it on traceback.

Without it, sphinx-autodoc-typehints is reported with an unknown version. See for example:

Versions
========

* Platform:         darwin; (macOS-15.5-arm64-64bit)
* Python version:   3.11.11 (CPython)
* Sphinx version:   8.2.3
* Docutils version: 0.21.2
* Jinja2 version:   3.1.6
* Pygments version: 2.19.2

Last Messages
=============

(...)

Loaded Extensions
=================

* sphinx.ext.mathjax (8.2.3)
* alabaster (1.0.0)
* sphinxcontrib.applehelp (2.0.0)
* sphinxcontrib.devhelp (2.0.0)
* sphinxcontrib.htmlhelp (2.1.0)
* sphinxcontrib.serializinghtml (2.0.0)
* sphinxcontrib.qthelp (2.0.0)
* sphinx.ext.autodoc.preserve_defaults (8.2.3)
* sphinx.ext.autodoc.type_comment (8.2.3)
* sphinx.ext.autodoc.typehints (8.2.3)
* sphinx.ext.autodoc (8.2.3)
* sphinx.ext.todo (8.2.3)
* sphinx.ext.intersphinx (8.2.3)
* sphinx.ext.viewcode (8.2.3)
* sphinx_copybutton (0.5.2)
* sphinx_design (0.6.1)
* sphinx_issues (5.0.1)
* sphinxext.opengraph (0.10.0)
* myst_parser (4.0.1)
* sphinx.ext.autosectionlabel (8.2.3)
* sphinx_autodoc_typehints (unknown version)
* click_extra.sphinx (5.1.0)
* sphinxcontrib.mermaid (8.2.3)
* furo (2025.07.19)
* sphinx_basic_ng (1.0.0.beta2)

Traceback
=========

(...)

[hoodmane]

Thanks!

[gaborbernat]

Can you add please a test to validate this behaviour happens?