Fix snap builds (#9729)

* release script change

* fix setup.py

* match setup.py logic

certbot-dns-digitalocean/setup.py

@@ -11,7 +11,9 @@ install_requires = [
     'setuptools>=41.6.0',
 ]
 
-if not os.environ.get('SNAP_BUILD'):
+if os.environ.get('SNAP_BUILD'):
+    install_requires.append('packaging')
+else:
     install_requires.extend([
         # We specify the minimum acme and certbot version as the current plugin
         # version for simplicity. See
@@ -19,11 +21,6 @@ if not os.environ.get('SNAP_BUILD'):
         f'acme>={version}',
         f'certbot>={version}',
     ])
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Unset SNAP_BUILD when building wheels '
-                       'to include certbot dependencies.')
-if os.environ.get('SNAP_BUILD'):
-    install_requires.append('packaging')
 
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags