fix(release): add Nix package steps to release molecule (#1108)

* fix(release): add Nix package steps to release molecule

Add missing Nix support to the release workflow:
- bump-default-nix: Updates version in default.nix
- update-vendorhash: Prompts to update vendorHash if go.mod changed
- Add default.nix to verify-versions check

This was lost when bump-version.sh was replaced with the molecule
workflow in 39dbe90a. The original Nix support from c802f27f included
vendorHash detection in bump-version.sh, but that logic was not
migrated to the new workflow.

Fixes #1107

* fix(nix): update vendorHash for current go.mod

default.nix

@@ -9,7 +9,7 @@ pkgs.buildGoModule {
   subPackages = [ "cmd/bd" ];
   doCheck = false;
   # Go module dependencies hash - if build fails with hash mismatch, update with the "got:" value
-  vendorHash = "sha256-mn2nnJ0o5Z1G7gy8d6qwY44iJe9vEmr+Eqwhmwpq6kU=";
+  vendorHash = "sha256-YU+bRLVlWtHzJ1QPzcKJ70f+ynp8lMoIeFlm+29BNPE=";
 
   # Git is required for tests
   nativeBuildInputs = [ pkgs.git ];