Flake8 and cleanup __pkginfo__

Drop useless stuff and make the file flake8-compliant.

Related to #17047898.

__pkginfo__.py

 # pylint: disable=W0622
 """cubicweb-rqlcontroller application packaging information"""
 
+from os.path import join
+from glob import glob
+
+
 modname = 'rqlcontroller'
 distname = 'cubicweb-rqlcontroller'
 
@@ -24,28 +28,12 @@ classifiers = [
     'Framework :: CubicWeb',
     'Programming Language :: Python',
     'Programming Language :: JavaScript',
-    ]
-
-from os import listdir as _listdir
-from os.path import join, isdir
-from glob import glob
+]
 
 THIS_CUBE_DIR = join('share', 'cubicweb', 'cubes', modname)
 
-def listdir(dirpath):
-    return [join(dirpath, fname) for fname in _listdir(dirpath)
-            if fname[0] != '.' and not fname.endswith('.pyc')
-            and not fname.endswith('~')
-            and not isdir(join(dirpath, fname))]
 
 data_files = [
     # common files
     [THIS_CUBE_DIR, [fname for fname in glob('*.py') if fname != 'setup.py']],
-    ]
-# check for possible extended cube layout
-for dname in ('entities', 'views', 'sobjects', 'hooks', 'schema', 'data', 'wdoc', 'i18n', 'migration'):
-    if isdir(dname):
-        data_files.append([join(THIS_CUBE_DIR, dname), listdir(dname)])
-# Note: here, you'll need to add subdirectories if you want
-# them to be included in the debian package
-
+]