treewide: use mkPackageOption

This commit replaces a lot of usages of `mkOption` with the package
type, to be `mkPackageOption`, in order to reduce the amount of code.

nixos/modules/services/backup/postgresql-wal-receiver.nix

@@ -5,12 +5,8 @@ with lib;
 let
   receiverSubmodule = {
     options = {
-      postgresqlPackage = mkOption {
-        type = types.package;
-        example = literalExpression "pkgs.postgresql_15";
-        description = lib.mdDoc ''
-          PostgreSQL package to use.
-        '';
+      postgresqlPackage = mkPackageOption pkgs "postgresql" {
+        example = "postgresql_15";
       };
 
       directory = mkOption {

nixos/modules/services/backup/restic-rest-server.nix

@@ -57,12 +57,7 @@ in
       '';
     };
 
-    package = mkOption {
-      default = pkgs.restic-rest-server;
-      defaultText = literalExpression "pkgs.restic-rest-server";
-      type = types.package;
-      description = lib.mdDoc "Restic REST server package to use.";
-    };
+    package = mkPackageOption pkgs "restic-rest-server" { };
   };
 
   config = mkIf cfg.enable {

nixos/modules/services/backup/restic.nix

@@ -245,14 +245,7 @@ in
           '';
         };
 
-        package = mkOption {
-          type = types.package;
-          default = pkgs.restic;
-          defaultText = literalExpression "pkgs.restic";
-          description = lib.mdDoc ''
-            Restic package to use.
-          '';
-        };
+        package = mkPackageOption pkgs "restic" { };
 
         createWrapper = lib.mkOption {
           type = lib.types.bool;

nixos/modules/services/backup/zrepl.nix

@@ -13,12 +13,7 @@ in
     services.zrepl = {
       enable = mkEnableOption (lib.mdDoc "zrepl");
 
-      package = mkOption {
-        type = types.package;
-        default = pkgs.zrepl;
-        defaultText = literalExpression "pkgs.zrepl";
-        description = lib.mdDoc "Which package to use for zrepl";
-      };
+      package = mkPackageOption pkgs "zrepl" { };
 
       settings = mkOption {
         default = { };