fix: use hatchling to build package

[d-v-b]

use hatchling instead of setuptools as the build system. Fixes #1357. I also add a test that ensures that the version of the package internally matches that reported by the built version.

[dimitri-yatsenko]

Review: Approved ✅

Verified the fix works correctly:

1. Build succeeds: python -m build --wheel produces datajoint-2.1.0a9-py3-none-any.whl

2. Subpackages included: The builtin_codecs subpackage is now correctly packaged:

   datajoint/builtin_codecs/__init__.py
   datajoint/builtin_codecs/attach.py
   datajoint/builtin_codecs/blob.py
   datajoint/builtin_codecs/filepath.py
   datajoint/builtin_codecs/hash.py
   datajoint/builtin_codecs/npy.py
   datajoint/builtin_codecs/object.py
   datajoint/builtin_codecs/schema.py
   

3. Import works: import datajoint succeeds (previously failed with ImportError: cannot import name 'builtin_codecs')

4. Version test passes: importlib.metadata.version('datajoint') == datajoint.__version__

Changes look good:

• Switching from setuptools to hatchling is a sensible modernization
• Removing setuptools from runtime dependencies is correct
• Using [project.scripts] instead of [project.entry-points."console_scripts"] is the modern standard
• The new version test is a useful regression guard

LGTM!