[Code scan] Use package version metadata in Sphinx configuration

[njzjz]

This issue was found by a Codex global code scan of the repository.

Affected code:

dargs/docs/conf.py

Lines 30 to 33 in b4db564

	# The short X.Y version
	version = "0.0"
	# The full version, including alpha/beta/rc tags
	release = "0.0.0-rc"

dargs/pyproject.toml

Lines 5 to 7 in b4db564

	[project]
	name = "dargs"
	dynamic = ["version"]

dargs/pyproject.toml

Lines 51 to 52 in b4db564

	[tool.setuptools_scm]
	write_to = "dargs/_version.py"

Problem:
The package version is dynamic via setuptools_scm, but the Sphinx configuration hard-codes placeholder metadata:

version = "0.0"
release = "0.0.0-rc"

Observed behavior:
Published documentation can show stale placeholder version values instead of the actual package version.

Expected behavior:
docs/conf.py should derive version and release from installed package metadata or setuptools-scm, with an explicit fallback for source-tree docs builds.