Unify dev-dep declaration to [project.optional-dependencies]

Switch from PEP 735 [dependency-groups] to PEP 508
[project.optional-dependencies] to match the three sibling packages in
the monorepo (python-dqlite-client, python-dqlite-dbapi,
sqlalchemy-dqlite). Update DEVELOPMENT.md's setup command to
``uv sync --extra dev`` and regenerate uv.lock.

Dev-dep contents unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: antoineleclair

DEVELOPMENT.md

@@ -12,7 +12,7 @@
 curl -LsSf https://astral.sh/uv/install.sh | sh
 
 # Create virtual environment and install dependencies
-uv sync --group dev
+uv sync --extra dev
 ```
 
 ## Development Tools

pyproject.toml

@@ -28,7 +28,7 @@ Homepage = "https://github.com/letsdiscodev/python-dqlite-wire"
 Repository = "https://github.com/letsdiscodev/python-dqlite-wire"
 Issues = "https://github.com/letsdiscodev/python-dqlite-wire/issues"
 
-[dependency-groups]
+[project.optional-dependencies]
 dev = ["pytest>=8.0", "pytest-cov>=4.0", "mypy>=1.0", "ruff>=0.4"]
 
 [tool.hatch.build.targets.wheel]