feat: switch from setup.cfg to pyproject.toml + hatchling

tasks.py

@@ -25,13 +25,24 @@ Tasks for rattail-fabric2
 """
 
 import os
+import re
 import shutil
 
 from invoke import task
 
 
 here = os.path.abspath(os.path.dirname(__file__))
-exec(open(os.path.join(here, 'rattail_fabric2', '_version.py')).read())
+__version__ = None
+pattern = re.compile(r'^version = "(\d+\.\d+\.\d+)"$')
+with open(os.path.join(here, 'pyproject.toml'), 'rt') as f:
+    for line in f:
+        line = line.rstrip('\n')
+        match = pattern.match(line)
+        if match:
+            __version__ = match.group(1)
+            break
+if not __version__:
+    raise RuntimeError("could not parse version!")
 
 
 @task
@@ -39,9 +50,10 @@ def release(c):
     """
     Release a new version of 'rattail-fabric2'.
     """
-    shutil.rmtree('rattail_fabric2.egg-info')
+    if os.path.exists('rattail_fabric2.egg-info'):
+        shutil.rmtree('rattail_fabric2.egg-info')
     # TODO: this seems heavy-handed? for sake of recursive-include in MANIFEST
     # TODO: what i esp. don't like is, this doesn't consider .gitignore
     c.run("find . -name '*~' -delete")
-    c.run('python setup.py sdist --formats=gztar')
+    c.run('python -m build --sdist')
     c.run(f'twine upload dist/rattail_fabric2-{__version__}.tar.gz')