Dedicated hack day to identify the top 5 issues that need attention

This was brought up during Astropy Coordination Meeting 2025 breakout on "dealing with stalled development efforts." This was one of the ways to encourage developers to address long-standing, open issues.

* Maybe do this for each `astropy` subpackage
* But there will be items that cross subpackages (elevate these in terms of priorities?)

Unclear from the notes when such a hack day would occur and who would attend. Maybe next Coordination Meeting, in another conference where there is a quorum of Astropy developers, dev telecon, or especially organized?

James Tocknell: *It may be worth identifying why such issues are open for so long? Is it because of lack of time from the maintainer to do the implementation, lack of time to get agreement from third parties (e.g., maintainers of other sub-packages or downstream), lack of time for design and/or something else.*

Start with the Astropy Coordination Meeting 2025 breakout notes referenced in the issue and review the proposed hack-day alternatives. Clarify when it would occur, who would attend, and whether each subpackage and cross-subpackage work is included. Done means the event scope, participation, prioritization approach, and reasons for stalled issues are documented.

Written by the indexing model from the issue text.