docs: remove feishu doc duplicate permission entry for im:message.p2p_msg:readonly

[John-Ferrel]

Summary

The permission im:message.p2p_msg:readonly appeared twice in the permission table with different descriptions.
This was caused by a leftover entry from a previous Feishu API migration, where the old scope im:message.p2p:receive was replaced but not fully cleaned up.
This PR removes the duplicate row, leaving only one entry with a consistent description.

Type of change

• Documentation only

Testing

• Verified the Markdown table renders correctly with the duplicate row removed.
• No functional change, so no automated tests required.

Manual / user-visible behavior change

Documentation readers will no longer see a confusing duplicate permission entry. The table now accurately reflects the current Feishu API scopes.

Related

• Root cause analysis:
  The original table had im:message.p2p:receive (接收单聊消息). After a Feishu API upgrade, this was unified into im:message.p2p_msg:readonly, but the old row was deleted and a new row was added, resulting in two rows for the same scope with different Chinese descriptions.
  This was confirmed via git blame on the affected file.
• Reference: Feishu Open Platform scope list