refactor(nix/buildLisp): use passthru for extra attributes r/2701

Using passthru and appending the attributes via `//` have the same
effect with a subtle difference: In the latter case re-evaluating
the derivation when using the underlying `mkDerivation`'s
`overrideAttrs` will delete all appended attributes. Using
passthru at least preserves the attributes although the self
reference to the derivation in `passthru.sbcl` will become
outdated (unless updated manually).

Change-Id: I8b85009f386b9375b86a23fd50c4ec8c6a9dea7f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3257
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
Reviewed-by: grfn <grfn@gws.fyi>

0 files changed, 0 insertions, 0 deletions