tests: Remove ignored `message_id` parameter in message edit tests.
tests: Remove ignored `message_id` parameter in message edit tests.

For PATCH requests to edit messages, the message ID is in the URL
and does not need to be passed as part of the data in tests.

zulip/zulip,zulip/zulip,zulip/zulip,zulip/zulip,zulip/zulip,zulip/zulip,zulip/zulip