ci/eval: don't evaluate variants

This removes pkgsx86_64Darwin from the top-level attributes when
generating attrpaths for evaluation on Linux. Needed for attrpaths
generation to succeed without silently catching eval errors.

Variants are still available during actual Eval for references from
other packages, just not during attrpath generation. To remove it from
Eval as well, issues around pkgsLLVM will have to be fixed first.

(cherry picked from commit fc45a5f2c9)

pkgs/by-name/bm/bmake/package.nix

@@ -4,7 +4,7 @@
   fetchurl,
   getopt,
   ksh,
-  pkgsMusl,
+  pkgsMusl ? { },
   stdenv,
   tzdata,
 }:
@@ -107,7 +107,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   passthru = {
     tests = {
-      bmakeMusl = pkgsMusl.bmake;
+      bmakeMusl = pkgsMusl.bmake or null;
     };
   };
 

pkgs/top-level/release-outpaths.nix

@@ -29,6 +29,7 @@ let
             allowBroken = includeBroken;
             allowUnfree = true;
             allowInsecurePredicate = x: true;
+            allowVariants = !attrNamesOnly;
             checkMeta = checkMeta;
 
             handleEvalIssue =