flake: remove release job

This is Hydra-specific and will be re-added in the commit adding a
release.nix.

Change-Id: I13900821b02fe268356932f612734187188832b8

flake.nix

@@ -116,43 +116,6 @@
       overlays.default = overlayFor (p: p.clangStdenv);
 
       hydraJobs = ciArtifacts // {
-        # Aggregate job that is finished in Hydra _after_ all constituent jobs (here: grouped by system)
-        # succeed.
-        # This is used to run CD scripts once all builds are finished on Hydra.
-        release = forAllSystems (
-          system:
-          let
-            pkgs = nixpkgsFor.${system}.native;
-          in
-          pkgs.runCommand "release"
-            {
-              _hydraAggregate = true;
-              constituents = lib.filter (x: x != null) (
-                lib.mapAttrsToListRecursiveCond
-                  (_: val: !(lib.isDerivation val || builtins.any (system': val ? ${system'}) systems))
-                  (
-                    path: drv:
-                    if drv ? ${system} then
-                      lib.concatStringsSep "." (path ++ [ system ])
-                    else if drv.system or null == system then
-                      lib.concatStringsSep "." path
-                    else
-                      null
-                  )
-                  (
-                    removeAttrs self.hydraJobs [
-                      "devShell"
-                      "release"
-                      "rl-next"
-                    ]
-                  )
-              );
-            }
-            ''
-              touch $out
-            ''
-        );
-
         devShell = forAllSystems (system: {
           default = self.devShells.${system}.default;
           clang = self.devShells.${system}.native-clangStdenvPackages;