Using finalAttrs.src.tag breaks if src is overriden to use rev #367739
Description
error: cannot coerce null to a string: null
Happens in dunst as it now does changelog = "https://github.com/dunst-project/dunst/blob/${finalAttrs.src.tag}/CHANGELOG.md";
The fix is to not use finalAttrs in meta.
https://github.com/NixOS/nixpkgs/pull/366584/files#r1896119706