Format .nix files

This does not include any automation for the release branch, but
is based on the configuration of https://github.com/NixOS/nix/pull/12349

    pre-commit run -a nixfmt-rfc-style

tests/nixos/functional/as-trusted-user.nix

@@ -4,7 +4,9 @@
   imports = [ ./common.nix ];
 
   nodes.machine = {
-    users.users.alice = { isNormalUser = true; };
+    users.users.alice = {
+      isNormalUser = true;
+    };
     nix.settings.trusted-users = [ "alice" ];
   };
 
@@ -15,4 +17,4 @@
       su --login --command "run-test-suite" alice >&2
     """)
   '';
-}
+}

tests/nixos/functional/as-user.nix

@@ -4,7 +4,9 @@
   imports = [ ./common.nix ];
 
   nodes.machine = {
-    users.users.alice = { isNormalUser = true; };
+    users.users.alice = {
+      isNormalUser = true;
+    };
   };
 
   testScript = ''

tests/nixos/functional/common.nix

@@ -2,9 +2,11 @@
 
 let
   # FIXME (roberth) reference issue
-  inputDerivation = pkg: (pkg.overrideAttrs (o: {
-    disallowedReferences = [ ];
-  })).inputDerivation;
+  inputDerivation =
+    pkg:
+    (pkg.overrideAttrs (o: {
+      disallowedReferences = [ ];
+    })).inputDerivation;
 
 in
 {
@@ -12,60 +14,70 @@ in
   # we skip it to save time.
   skipTypeCheck = true;
 
-  nodes.machine = { config, pkgs, ... }: {
+  nodes.machine =
+    { config, pkgs, ... }:
+    {
 
-    virtualisation.writableStore = true;
-    system.extraDependencies = [
-      (inputDerivation config.nix.package)
-    ];
+      virtualisation.writableStore = true;
+      system.extraDependencies = [
+        (inputDerivation config.nix.package)
+      ];
 
-    nix.settings.substituters = lib.mkForce [];
+      nix.settings.substituters = lib.mkForce [ ];
 
-    environment.systemPackages = let
-      run-test-suite = pkgs.writeShellApplication {
-        name = "run-test-suite";
-        runtimeInputs = [ pkgs.gnumake pkgs.jq pkgs.git ];
-        text = ''
-          set -x
-          cat /proc/sys/fs/file-max
-          ulimit -Hn
-          ulimit -Sn
-          cd ~
-          cp -r ${pkgs.nix.overrideAttrs (o: {
-            name = "nix-configured-source";
-            outputs = [ "out" ];
-            separateDebugInfo = false;
-            disallowedReferences = [ ];
-            buildPhase = ":";
-            checkPhase = ":";
-            installPhase = ''
-              cp -r . $out
+      environment.systemPackages =
+        let
+          run-test-suite = pkgs.writeShellApplication {
+            name = "run-test-suite";
+            runtimeInputs = [
+              pkgs.gnumake
+              pkgs.jq
+              pkgs.git
+            ];
+            text = ''
+              set -x
+              cat /proc/sys/fs/file-max
+              ulimit -Hn
+              ulimit -Sn
+              cd ~
+              cp -r ${
+                pkgs.nix.overrideAttrs (o: {
+                  name = "nix-configured-source";
+                  outputs = [ "out" ];
+                  separateDebugInfo = false;
+                  disallowedReferences = [ ];
+                  buildPhase = ":";
+                  checkPhase = ":";
+                  installPhase = ''
+                    cp -r . $out
+                  '';
+                  installCheckPhase = ":";
+                  fixupPhase = ":";
+                  doInstallCheck = true;
+                })
+              } nix
+              chmod -R +w nix
+              cd nix
+
+              # Tests we don't need
+              echo >tests/functional/plugins/local.mk
+              sed -i tests/functional/local.mk \
+                -e 's!nix_tests += plugins\.sh!!' \
+                -e 's!nix_tests += test-libstoreconsumer\.sh!!' \
+                ;
+
+              export isTestOnNixOS=1
+              export version=${config.nix.package.version}
+              export NIX_REMOTE_=daemon
+              export NIX_REMOTE=daemon
+              export NIX_STORE=${builtins.storeDir}
+              make -j1 installcheck --keep-going
             '';
-            installCheckPhase = ":";
-            fixupPhase = ":";
-            doInstallCheck = true;
-          })} nix
-          chmod -R +w nix
-          cd nix
-
-          # Tests we don't need
-          echo >tests/functional/plugins/local.mk
-          sed -i tests/functional/local.mk \
-            -e 's!nix_tests += plugins\.sh!!' \
-            -e 's!nix_tests += test-libstoreconsumer\.sh!!' \
-            ;
-
-          export isTestOnNixOS=1
-          export version=${config.nix.package.version}
-          export NIX_REMOTE_=daemon
-          export NIX_REMOTE=daemon
-          export NIX_STORE=${builtins.storeDir}
-          make -j1 installcheck --keep-going
-        '';
-      };
-    in [
-      run-test-suite
-      pkgs.git
-    ];
-  };
+          };
+        in
+        [
+          run-test-suite
+          pkgs.git
+        ];
+    };
 }

tests/nixos/functional/symlinked-home.nix

@@ -16,7 +16,9 @@
   imports = [ ./common.nix ];
 
   nodes.machine = {
-    users.users.alice = { isNormalUser = true; };
+    users.users.alice = {
+      isNormalUser = true;
+    };
   };
 
   testScript = ''