check-meta: wrap maintainers attribute to include team members (#402991)

ci/eval/compare/maintainers.nix

···
     // {
       # TODO: Refactor this so we can ping entire teams instead of the individual members.
       # Note that this will require keeping track of GH team IDs in "maintainers/teams.nix".
-      maintainers =
-        meta.maintainers or [ ]
-        ++ lib.flatten (map (team: team.members or [ ]) (meta.teams or [ ]));
+      maintainers = meta.maintainers or [ ];
     }
   ) attrsWithPackages;
 
···
     (lib.lists.unique (
       builtins.map (pos: lib.strings.removePrefix (toString ../..) pos.file) (
         builtins.filter (x: x != null) [
-          (builtins.unsafeGetAttrPos "maintainers" (drv.meta or { }))
+          ((drv.meta or { }).maintainersPosition or null)
+          ((drv.meta or { }).teamsPosition or null)
           (builtins.unsafeGetAttrPos "src" drv)
           # broken because name is always set by stdenv:
           #    # A hack to make `nix-env -qa` and `nix search` ignore broken packages.

pkgs/stdenv/generic/check-meta.nix

···
       isFcitxEngine = bool;
       isIbusEngine = bool;
       isGutenprint = bool;
+
+      # Used for the original location of the maintainer and team attributes to assist with pings.
+      maintainersPosition = any;
+      teamsPosition = any;
     };
 
   checkMetaAttr =
···
         )
       ] ++ optional (hasOutput "man") "man";
     }
+    // {
+      # CI scripts look at these to determine pings.
+      maintainersPosition = builtins.unsafeGetAttrPos "maintainers" (attrs.meta or { });
+      teamsPosition = builtins.unsafeGetAttrPos "teams" (attrs.meta or { });
+    }
     // attrs.meta or { }
     # Fill `meta.position` to identify the source location of the package.
     // optionalAttrs (pos != null) {
       position = pos.file + ":" + toString pos.line;
+    }
+    // {
+      # Maintainers should be inclusive of teams.
+      # Note that there may be external consumers of this API (repology, for instance) -
+      # if you add a new maintainer or team attribute please ensure that this expectation is still met.
+      maintainers =
+        attrs.meta.maintainers or [ ]
+        ++ concatMap (team: team.members or [ ]) attrs.meta.teams or [ ];
     }
     // {
       # Expose the result of the checks for everyone to see.