Fix a bug that deploy pr messages trigger other actions also

[tomoasleep]

This PR fixes a bug that the message @qiitan deploy pull request ... triggers other actions (such as ruboty-talk actions) in addition to the pull request action.

(In this conversation, Ruboty creates deploy pull request in reply to my message. However, ruboty-talk's handler is also executed and a reply message is sent.)

The reason why other actions are triggered is that Ruboty judges the given message is not matched to the action if the handler of the action returns falsy value and Ruboty tries to call other handlers.
We modify Ruboty::Github::Actions::CreatePullRequest#call to always return truthy value to tell Ruboty the given message is matched and handled.

References

• Implementation of processing handlers
  • https://github.com/r7kamura/ruboty/blob/69b89b0f46d9404c142d78d4e82e2d90b05a2248/lib/ruboty/handlers/base.rb#L32
  • https://github.com/r7kamura/ruboty/blob/69b89b0f46d9404c142d78d4e82e2d90b05a2248/lib/ruboty/robot.rb#L29

[yujinakayama]

👍

[tomoasleep]

thx!