tests: exclude bundled pywatchman from check-code test

pywatchman is imported from upstream and therefore fails to pass
linting. We have added 'no-check-code' manually to every file in the
past. This is cumbersome and modifies upstream sources.

tests/test-check-code.t

@@ -1,36 +1,31
 #require test-repo
 
   $ . "$TESTDIR/helpers-testrepo.sh"
   $ check_code="$TESTDIR"/../contrib/check-code.py
   $ cd "$TESTDIR"/..
 
 New errors are not allowed. Warnings are strongly discouraged.
 (The writing "no-che?k-code" is for not skipping this file when checking.)
 
-  $ hg locate -X contrib/python-zstandard | sed 's-\\-/-g' |
-  >   xargs "$check_code" --warnings --per-file=0 || false
-  Skipping hgext/fsmonitor/pywatchman/__init__.py it has no-che?k-code (glob)
-  Skipping hgext/fsmonitor/pywatchman/bser.c it has no-che?k-code (glob)
-  Skipping hgext/fsmonitor/pywatchman/capabilities.py it has no-che?k-code (glob)
-  Skipping hgext/fsmonitor/pywatchman/msc_stdint.h it has no-che?k-code (glob)
-  Skipping hgext/fsmonitor/pywatchman/pybser.py it has no-che?k-code (glob)
+  $ hg locate -X contrib/python-zstandard -X hgext/fsmonitor/pywatchman |
+  > sed 's-\\-/-g' | xargs "$check_code" --warnings --per-file=0 || false
   Skipping i18n/polib.py it has no-che?k-code (glob)
   Skipping mercurial/httpclient/__init__.py it has no-che?k-code (glob)
   Skipping mercurial/httpclient/_readers.py it has no-che?k-code (glob)
   Skipping mercurial/statprof.py it has no-che?k-code (glob)
 
 @commands in debugcommands.py should be in alphabetical order.
 
   >>> import re
   >>> commands = []
   >>> with open('mercurial/debugcommands.py', 'rb') as fh:
   ...     for line in fh:
   ...         m = re.match("^@command\('([a-z]+)", line)
   ...         if m:
   ...             commands.append(m.group(1))
   >>> scommands = list(sorted(commands))
   >>> for i, command in enumerate(scommands):
   ...     if command != commands[i]:
   ...         print('commands in debugcommands.py not sorted; first differing '
   ...               'command is %s; expected %s' % (commands[i], command))
   ...         break