fix combined queues and remove broken retry log link for multi repo queues

[Skgland]

[Mark-Simulacrum]

I would prefer to drop support for showing a queue across multiple repositories, rather than trying to fix it. I don't think we need that feature, and dropping support seems likely to be safer/simpler/more maintainable in the long run.

[Skgland]

Removing combined queues appears reasonable given how long this breakage went unnoticed, but I like to view the "all" queue as I find it gives a nice overview.