check-code: drop the camelcase checks

Fro about 2 years we have been using CamelCase is class names. That rules gets
in the way of assigning class or exception in compatibility layers.

I think it is safe to drop it now that we started using CamelCase for some case.

My motivation for this is the need to assign `FileNotFoundError` in `pycompat`.

Differential Revision: https://phab.mercurial-scm.org/D11309

contrib/check-code.py

@@ -340,11 +340,6 b' commonpypats = ['
         (r'[^\n]\Z', "no trailing newline"),
         (r'(\S[ \t]+|^[ \t]+)\n', "trailing whitespace"),
         (
-            r'^\s+(self\.)?[A-Za-z][a-z0-9]+[A-Z]\w* = ',
-            "don't use camelcase in identifiers",
-            r'#.*camelcase-required',
-        ),
-        (
             r'^\s*(if|while|def|class|except|try)\s[^[\n]*:\s*[^\\n]#\s]+',
             "linebreak after :",
         ),