emacs: allow specifying meta in sources

pkgs/applications/editors/emacs/make-emacs.nix

@@ -538,10 +538,10 @@ mkDerivation (finalAttrs: {
     };
   };
 
-  meta = meta // {
+  meta = {
     broken = withNativeCompilation && !(stdenv.buildPlatform.canExecute stdenv.hostPlatform);
     knownVulnerabilities = lib.optionals (lib.versionOlder version "30") [
       "CVE-2024-53920 CVE-2025-1244, please use newer versions such as emacs30"
     ];
-  };
+  } // meta;
 })

pkgs/applications/editors/emacs/sources.nix

@@ -13,6 +13,7 @@ let
       patches ? _: [ ],
       rev,
       hash,
+      meta ? { },
     }:
     {
       inherit
@@ -97,7 +98,7 @@ let
           }
           .${variant};
         mainProgram = "emacs";
-      };
+      } // meta;
     };
 in
 {