[master] Fix await None error

[merlinz01]

What does this PR do?

Adds @tornado.gen.coroutine decorator to Minion._handle_payload method (also ProxyMinion and Syndic).

What issues does this PR fix or reference?

Fixes: #66177

Previous Behavior

Traceback (most recent call last):
  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/transport/zeromq.py", line 394, in consume
     await callback(msg)
  File "/opt/saltstack/salt/lib/python3.10/site-packages/salt/channel/client.py", line 484, in wrap_callback
    await callback(decoded)
TypeError: object NoneType can't be used in 'await' expression

New Behavior

No errors!

Merge requirements satisfied?

[NOTICE] Bug fixes or features added to Salt require tests.

• Docs
• Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
• Tests written/updated

Commits signed with GPG?

No

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[tjyang]

#66282, I opened this ticket to track time out issue.

[dwoz]

Please hold off on merging this until I have a chance to look at it in more detail. See also #66231

[merlinz01]

Have updated this PR according to the recommendations in this comment.

[dwoz]

superseded by #66335