check-code: remove ban on old-style classes

In Python 3, `class foo:` is equivalent to `class foo(object):`. So
we can allow the former form now.

Differential Revision: https://phab.mercurial-scm.org/D12351

contrib/check-code.py

@@ -343,16 +343,6 b' commonpypats = ['
             "linebreak after :",
         ),
         (
-            r'class\s[^( \n]+:',
-            "old-style class, use class foo(object)",
-            r'#.*old-style',
-        ),
-        (
-            r'class\s[^( \n]+\(\):',
-            "class foo() creates old style object, use class foo(object)",
-            r'#.*old-style',
-        ),
-        (
             r'\b(%s)\('
             % '|'.join(k for k in keyword.kwlist if k not in ('print', 'exec')),
             "Python keyword is not a function",

tests/test-contrib-check-code.t

@@ -51,12 +51,6 b''
   ./quote.py:5:
    > '"""', 42+1, """and
    missing whitespace in expression
-  ./classstyle.py:4:
-   > class oldstyle_class:
-   old-style class, use class foo(object)
-  ./classstyle.py:7:
-   > class empty():
-   class foo() creates old style object, use class foo(object)
   [1]
   $ cat > python3-compat.py << NO_CHECK_EOF
   > foo <> bar