[Development] Cherry-picks lost and forgotten

[Edward Welbourne]

Hi all,

Today I noticed, when pushing a conflict-fix for a cherry-pick, that
Gerrit puts the Owner into the attention list, but no-one else.  As the
owner is the cherry-pick 'bot, this isn't very helpful.

I've subsequently been looking through the (hundreds of) open reviews
owned by the 'bot and finding the ones that have no attention set.
Aside from the ones that are due to the above, of which there are
plenty, I have found quite a few where the CI rejected a change but
no-one got added to the review.  We may be able to do something about
that, but that'll probably only catch future examples (albeit I restaged
the ones I noticed), so I encourage everyone to:
* manually add some reviewers to the attention set when you push a
  conflict-fix, and
* review [0] (self's open picks) and [1] (which Marc calls "Lost
  Treasures") regularly to see if anything of yours is dangling.

[0] https://codereview.qt-project.org/q/owner:cherrypick_bot%2540qt-project.org+status:open+author:self
[1] https://codereview.qt-project.org/q/attention:self+NOT+branch:dev

In particular, add someone to the attention set of anything in [0] that
has no-one and needs attention,

	Eddy.