treewide: remove redundant parenthesis in nix code

default.nix

@@ -517,7 +517,7 @@ in
       type = let
         loginAccount = mkOptionType {
           name = "Login Account";
-          check = (account: builtins.elem account (builtins.attrNames cfg.loginAccounts));
+          check = account: builtins.elem account (builtins.attrNames cfg.loginAccounts);
         };
       in with types; attrsOf (either loginAccount (nonEmptyListOf loginAccount));
       example = {
@@ -901,7 +901,7 @@ in
       };
 
       domain = mkOption {
-        type = types.enum (cfg.domains);
+        type = types.enum cfg.domains;
         example = "example.com";
         description = ''
           The domain from which outgoing DMARC reports are served.

mail-server/dovecot.nix

@@ -148,7 +148,7 @@ in
     ];
 
     warnings =
-      (lib.optional (
+      lib.optional (
         (builtins.length cfg.fullTextSearch.languages > 1) &&
         (builtins.elem "stopwords" cfg.fullTextSearch.filters)
       ) ''
@@ -158,7 +158,7 @@ in
 
         The recommended solution is to NOT use the stopword filter when
         multiple languages are present in the configuration.
-      '')
+      ''
     ;
 
     # for sieve-test. Shelling it in on demand usually doesnt' work, as it reads

mail-server/postfix.nix

@@ -75,23 +75,23 @@ let
   in builtins.toFile "regex_valias" content;
 
   # denied_recipients_postfix :: [ String ]
-  denied_recipients_postfix = (map
+  denied_recipients_postfix = map
     (acct: "${acct.name} REJECT ${acct.sendOnlyRejectMessage}")
-    (lib.filter (acct: acct.sendOnly) (lib.attrValues cfg.loginAccounts)));
+    (lib.filter (acct: acct.sendOnly) (lib.attrValues cfg.loginAccounts));
   denied_recipients_file = builtins.toFile "denied_recipients" (lib.concatStringsSep "\n" denied_recipients_postfix);
 
-  reject_senders_postfix = (map
+  reject_senders_postfix = map
     (sender:
       "${sender} REJECT")
-    (cfg.rejectSender));
-  reject_senders_file = builtins.toFile "reject_senders" (lib.concatStringsSep "\n" (reject_senders_postfix))  ;
+    cfg.rejectSender;
+  reject_senders_file = builtins.toFile "reject_senders" (lib.concatStringsSep "\n" reject_senders_postfix)  ;
 
-  reject_recipients_postfix = (map
+  reject_recipients_postfix = map
     (recipient:
       "${recipient} REJECT")
-    (cfg.rejectRecipients));
+    cfg.rejectRecipients;
   # rejectRecipients :: [ Path ]
-  reject_recipients_file = builtins.toFile "reject_recipients" (lib.concatStringsSep "\n" (reject_recipients_postfix))  ;
+  reject_recipients_file = builtins.toFile "reject_recipients" (lib.concatStringsSep "\n" reject_recipients_postfix)  ;
 
   # vhosts_file :: Path
   vhosts_file = builtins.toFile "vhosts" (concatStringsSep "\n" cfg.domains);
@@ -231,7 +231,7 @@ in
         virtual_mailbox_domains = vhosts_file;
         virtual_mailbox_maps = [
           (mappedFile "valias")
-        ] ++ lib.optionals (cfg.ldap.enable) [
+        ] ++ lib.optionals cfg.ldap.enable [
           "ldap:${ldapVirtualMailboxMapFile}"
         ] ++ lib.optionals (regex_valiases_postfix != {}) [
           (mappedRegexFile "regex_valias")

mail-server/rspamd.nix

@@ -171,7 +171,7 @@ in
       ];
     };
 
-    systemd.services.rspamd-dmarc-reporter = lib.optionalAttrs (cfg.dmarcReporting.enable) {
+    systemd.services.rspamd-dmarc-reporter = lib.optionalAttrs cfg.dmarcReporting.enable {
       # Explicitly select yesterday's date to work around broken
       # default behaviour when called without a date.
       # https://github.com/rspamd/rspamd/issues/4062
@@ -216,7 +216,7 @@ in
       };
     };
 
-    systemd.timers.rspamd-dmarc-reporter = lib.optionalAttrs (cfg.dmarcReporting.enable) {
+    systemd.timers.rspamd-dmarc-reporter = lib.optionalAttrs cfg.dmarcReporting.enable {
       description = "Daily delivery of aggregated DMARC reports";
       wantedBy = [
         "timers.target"

mail-server/users.nix

@@ -70,17 +70,17 @@ let
 in {
   config = lib.mkIf enable {
     # assert that all accounts provide a password
-    assertions = (map (acct: {
-      assertion = (acct.hashedPassword != null || acct.hashedPasswordFile != null);
+    assertions = map (acct: {
+      assertion = acct.hashedPassword != null || acct.hashedPasswordFile != null;
       message = "${acct.name} must provide either a hashed password or a password hash file";
-    }) (lib.attrValues loginAccounts));
+    }) (lib.attrValues loginAccounts);
 
     # warn for accounts that specify both password and file
-    warnings = (map
+    warnings = map
       (acct: "${acct.name} specifies both a password hash and hash file; hash file will be used")
       (lib.filter
         (acct: (acct.hashedPassword != null && acct.hashedPasswordFile != null))
-        (lib.attrValues loginAccounts)));
+        (lib.attrValues loginAccounts));
 
     # set the vmail gid to a specific value
     users.groups = {