chore(nixpkgs): Bump channels to 2021-05-25

* users/grfn/system/home/yeren: remove obsolete awscli2 overrides

* ops: make new isSystemUser || isNormalUser assertion happy

* users/grfn/system/system/mugwump: make buildkite agents system users

* users/tazjin/nixos/camden: set isSystemUser = true for git

* users/tazjin/emacs: Remove missing & broken packages

* third_party/openldap: remove, as the argon2 module is now enabled upstream

* third_party/gerrit_plugins: Pinned new unstable hashes

* third_party/nix, third_party/grpc: Disabled CI as these are broken

* third_party/overlays/emacs: Bumped version to stay in sync with channel

* third_party/buzz: Update LIBCLANG_PATH to reference libclang.lib,
  since libclang's default output no longer contains libclang.so

* users/grfn/system/home: Install julia-stable instead of julia (which
  aliases to julia-lts), as the latter depends on an insecure version of
  libgit

Change-Id: Iff33b0ecb0ef07a82d1de35e23c40d2f4bf0f8ed
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3001
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>

users/grfn/system/home/machines/yeren.nix

@@ -39,16 +39,7 @@ in
 
     steam
 
-    (awscli2.overridePythonAttrs (oldAttrs: {
-      postPatch = ''
-        substituteInPlace setup.py \
-          --replace 'colorama>=0.2.5,<0.4.4' 'colorama'  \
-          --replace 'wcwidth<0.2.0' 'colorama' \
-          --replace 'cryptography>=2.8.0,<=2.9.0' 'cryptography' \
-          --replace 'docutils>=0.10,<0.16' 'docutils' \
-          --replace 'ruamel.yaml>=0.15.0,<0.16.0' 'ruamel.yaml'
-      '';
-    }))
+    awscli2
   ];
 
   systemd.user.services.laptop-keyboard = {

users/grfn/system/home/modules/development.nix

@@ -76,7 +76,7 @@ with lib;
 
     nodePackages.prettier
   ] ++ optionals (stdenv.isLinux) [
-    julia
+    julia-stable
     valgrind
   ];
 

users/grfn/system/system/machines/mugwump.nix

@@ -274,6 +274,12 @@ with lib;
     };
   }) (range 1 1));
 
-  users.users."buildkite-agent-mugwump-1".extraGroups = [ "docker" ];
-  users.users."buildkite-agent-mugwump-2".extraGroups = [ "docker" ];
+  users.users."buildkite-agent-mugwump-1" = {
+    isSystemUser = true;
+    extraGroups = [ "docker" ];
+  };
+  users.users."buildkite-agent-mugwump-2" = {
+    isSystemUser = true;
+    extraGroups = [ "docker" ];
+  };
 }