This attribute was supposed to be set on derivations, to make the
release tools recurse into them. The remaining uses were all on regular
attrsets, though, so this is safe to remove.
The following changes were made:
- Using `lib.` instead of `builtins.`
- Using `mapAttrsToList` instead of `mapAttrs` + `attrValues`
- Joining two of the if conditions with the same return value
- Using `traceIf` instead of `if` / `else`
- Using `showAttrPath` instead of `concatStringsSep`
This condition doesn't make a difference anymore, ever since we removed
the tryEval code from this file and had already enabled unfree packages
earlier anyway.
By now, these files have been changed enough to not need the "vendored
from" notes anymore. These links would still be there when going through
the history of the file, but today GHA CI has not many similarities
anymore to what ofborg did, so these are not really helpful.
These files are tightly coupled with the code in ci/eval and not used
anywhere else. They are subject to the same backporting requirements as
the remaining CI code. They are better placed next here.
