py24: remove check-code py24 notation

We require python2.6+

contrib/check-code.py

@@ -14,7 +14,7 b' when a rule triggers wrong, do one of th'
  * doublecheck that it is a false match
  * improve the rule pattern
  * add an ignore pattern to the rule (3rd arg) which matches your good line
-   (you can append a short comment and match this, like: #re-raises, # no-py24)
+   (you can append a short comment and match this, like: #re-raises)
  * change the pattern to a warning and list the exception in test-check-code-hg
  * ONLY use no--check-code for skipping entire files from external sources
 """

contrib/import-checker.py

@@ -200,10 +200,8 b' def list_stdlib_modules():'
             stdlib_prefixes.add(dirname)
     for libpath in sys.path:
         # We want to walk everything in sys.path that starts with
-        # something in stdlib_prefixes. check-code suppressed because
-        # the ast module used by this script implies the availability
-        # of any().
-        if not any(libpath.startswith(p) for p in stdlib_prefixes): # no-py24
+        # something in stdlib_prefixes.
+        if not any(libpath.startswith(p) for p in stdlib_prefixes):
             continue
         for top, dirs, files in os.walk(libpath):
             for i, d in reversed(list(enumerate(dirs))):