ci: a better way than commenting out external repos

[dimaqq]

Proposing a fix to #1461 deleting commented out repos

[benhoyt]

Looks like a reasonable approach -- thanks.

[tonyandrewmeyer]

So I gather what will happen here is that the commit line will still get bumped, but it will remain disabled. That seems reasonable to me.

I do think we need to document this somewhere, though. That could just be a disabled: false on the ones that are ok, or maybe it should be in HACKING.md or the action's readme.md or somewhere? Otherwise once nothing is disabled, it won't be obvious that this is how you do it (although the if will still be there).

I didn't actually run the script to verify that this will probably work, but looking over the code it seems like it, and we'll see soon enough if not, and it wouldn't be disruptive anyway.