gclient: remove hookinfo command

It's unused, and not covered by tests.

See https://codereview.chromium.org/9232068/ where it was added ~5 years ago
for an abandoned project to convert to repo.

Bug: 570091
Change-Id: Ica59cd3b28f92e05607203218cbeb92a377ec99a
Reviewed-on: https://chromium-review.googlesource.com/534313
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Paweł Hajdan Jr. <phajdan.jr@chromium.org>

gclient.py

@@ -2311,18 +2311,6 @@ def CMDrevinfo(parser, args):
   return 0
 
 
-def CMDhookinfo(parser, args):
-  """Outputs the hooks that would be run by `gclient runhooks`."""
-  (options, args) = parser.parse_args(args)
-  options.force = True
-  client = GClient.LoadCurrentConfig(options)
-  if not client:
-    raise gclient_utils.Error('client not configured; see \'gclient config\'')
-  client.RunOnDeps(None, [])
-  print('; '.join(' '.join(hook) for hook in client.GetHooks(options)))
-  return 0
-
-
 def CMDverify(parser, args):
   """Verifies the DEPS file deps are only from allowed_hosts."""
   (options, args) = parser.parse_args(args)