chore: use new nixpkgs with overlay which bring back go_1_20 instead of using old nixpkgs (#1162)

default.nix

@@ -11,6 +11,7 @@
       }
   ),
   buildGoApplication ? pkgs.buildGoApplication,
+  ...
 }:
 buildGoApplication {
   pname = "ZeroBot-Plugin";

flake.lock

@@ -28,11 +28,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1741396135,
-        "narHash": "sha256-wqmdLr7h4Bk8gyKutgaApJKOM8JVvywI5P48NuqJ9Jg=",
+        "lastModified": 1742209644,
+        "narHash": "sha256-jMy1XqXqD0/tJprEbUmKilTkvbDY/C0ZGSsJJH4TNCE=",
         "owner": "nix-community",
         "repo": "gomod2nix",
-        "rev": "0983848bf2a7ccbfe24d874065adb8fd0f23729b",
+        "rev": "8f3534eb8f6c5c3fce799376dc3b91bae6b11884",
         "type": "github"
       },
       "original": {
@@ -42,6 +42,22 @@
       }
     },
     "nixpkgs": {
+      "locked": {
+        "lastModified": 1745391562,
+        "narHash": "sha256-sPwcCYuiEopaafePqlG826tBhctuJsLx/mhKKM5Fmjo=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "8a2f738d9d1f1d986b5a4cd2fd2061a7127237d7",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-with-go_1_20": {
       "locked": {
         "lastModified": 1710843028,
         "narHash": "sha256-CMbK45c4nSkGvayiEHFkGFH+doGPbgo3AWfecd2t1Fk=",
@@ -61,7 +77,8 @@
       "inputs": {
         "flake-utils": "flake-utils",
         "gomod2nix": "gomod2nix",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-with-go_1_20": "nixpkgs-with-go_1_20"
       }
     },
     "systems": {

flake.nix

@@ -1,8 +1,8 @@
 {
   description = "基于 ZeroBot 的 OneBot 插件";
 
-  # pin nixpkgs to preserve dropped go_1_20
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/33c51330782cb486764eb598d5907b43dc87b4c2";
+  inputs.nixpkgs-with-go_1_20.url = "github:NixOS/nixpkgs/33c51330782cb486764eb598d5907b43dc87b4c2";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
   inputs.flake-utils.url = "github:numtide/flake-utils";
   inputs.gomod2nix.url = "github:nix-community/gomod2nix";
   inputs.gomod2nix.inputs.nixpkgs.follows = "nixpkgs";
@@ -11,14 +11,25 @@
   outputs = {
     self,
     nixpkgs,
+    nixpkgs-with-go_1_20,
     flake-utils,
     gomod2nix,
-  }: let
+    ...
+  } @ inputs: let
     allSystems = flake-utils.lib.allSystems;
   in (
     flake-utils.lib.eachSystem allSystems
     (system: let
-      pkgs = nixpkgs.legacyPackages.${system};
+      old-nixpkgs = nixpkgs-with-go_1_20.legacyPackages.${system};
+      pkgs = import nixpkgs {
+        inherit system;
+
+        overlays = [
+          (_: _: {
+            go_1_20 = old-nixpkgs.go_1_20;
+          })
+        ];
+      };
 
       # The current default sdk for macOS fails to compile go projects, so we use a newer one for now.
       # This has no effect on other platforms.
@@ -26,11 +37,10 @@
     in {
       # doCheck will fail at write files
       packages = rec {
-
-        ZeroBot-Plugin =
-          (callPackage ./. {
+        ZeroBot-Plugin = (callPackage ./. (inputs
+          // {
             inherit (gomod2nix.legacyPackages.${system}) buildGoApplication;
-          })
+          }))
           .overrideAttrs (_: {doCheck = false;});
 
         default = ZeroBot-Plugin;
@@ -43,7 +53,6 @@
             pkgs.cacert
           ];
         };
-
       };
       devShells.default = callPackage ./shell.nix {
         inherit (gomod2nix.legacyPackages.${system}) mkGoEnv gomod2nix;

shell.nix

@@ -13,7 +13,7 @@
   mkGoEnv ? pkgs.mkGoEnv,
   gomod2nix ? pkgs.gomod2nix,
 }: let
-  goEnv = mkGoEnv {pwd = ./.;};
+  goEnv = mkGoEnv { pwd = ./.; go = pkgs.go_1_20; };
 in
   pkgs.mkShell {
     packages = [