fix: remove deprecated Task.yield call

[seuros]

Summary

Task.yield is deprecated with no replacement (warning appears in Ruby 3.4+).

The call was redundant since self.wait already blocks and yields to other fibers through the condition variable.

Changes

Simplified the gardener loop from:

while true
  if @policy
    @policy.call(self)
  else
    Task.yield
  end
  self.wait
end

To:

while true
  @policy&.call(self)
  self.wait
end

Test plan

• All 40 existing tests pass

[ioquatix]

This PR was a bit hard to merge, so I did it by hand and released in v0.11.1.

Thanks for your efforts and bringing this to my attention.

[seuros]

Sorry, i did not see the trailing space removal, i use the dictator on watch mode. So it just auto fixed them.

[ioquatix]

It's all good. Thanks again.