nix: update for nixpkgs 25.11

mmgen/data/version

@@ -1 +1 @@
-16.1.dev20
+16.1.dev21

mmgen/proto/btc/regtest.py

@@ -104,9 +104,7 @@ class MMGenRegtest(MMGenObject):
 	@property
 	async def miner_wif(self):
 		if not hasattr(self, '_miner_wif'):
-			self._miner_wif = (
-				self.bdb_miner_wif if self.bdb_wallet else
-				await self.rpc_call('dumpprivkey', (await self.miner_addr), wallet='miner'))
+			self._miner_wif = self.bdb_miner_wif if self.bdb_wallet else None
 		return self._miner_wif
 
 	def create_hdseed_wif(self):

nix/merged-packages.nix

@@ -1,7 +1,7 @@
 { add_pkgs_path }:
 
 let
-    dfl_nixpkgs = import ./nixpkgs-25.05.nix {};
+    dfl_nixpkgs = import ./nixpkgs-25.11.nix {};
     dfl_python = pkgs.python313;
     null_pkgs = {
         system-packages = {};

nix/nixpkgs-25.05.nix

@@ -1,9 +0,0 @@
-import (
-    fetchGit {
-        url = "https://github.com/NixOS/nixpkgs.git";
-        # url = /path/to/repo/nixpkgs-25.05.git;
-        ref = "release-25.05";
-        rev = "11cb3517b3af6af300dd6c055aeda73c9bf52c48"; # refs/tags/25.05
-        shallow = true;
-    }
-)

nix/nixpkgs-25.11.nix

@@ -0,0 +1,9 @@
+import (
+    fetchGit {
+        url = "https://github.com/NixOS/nixpkgs.git";
+        # url = /path/to/repo/nixpkgs-25.11.git;
+        ref = "release-25.11";
+        rev = "52de6ea1db373aac4aec2ca926638db524ea7acf";
+        shallow = true;
+    }
+)

nix/reth.nix

@@ -1,20 +1,8 @@
 {
     lib,
+    pkgs,
 }:
 
-let
-    # cargo and rustc packages from 25.05 are out of date,
-    # so fetch them from a more recent commit:
-    pinnedPkgs = fetchGit {
-        url = "https://github.com/NixOS/nixpkgs.git";
-        # url = /path/to/repo/nixpkgs-fe8997.git;
-        rev = "fe89979ad5e8fd233ae0aac0e7e56f465945ae70";
-        shallow = true;
-    };
-    pkgs = import pinnedPkgs {};
-
-in
-
 pkgs.rustPlatform.buildRustPackage rec {
     pname = "reth";
     version = "1.9.3";

nix/user-packages.nix

@@ -8,7 +8,7 @@
 rec {
     ### Set nixpkgs globally for the MMGen environment.
     ### If you set it, make sure to uncomment the python variable assignment below.
-    # pkgs = import (bdir + /nixpkgs-25.05.nix) {};
+    # pkgs = import (bdir + /nixpkgs-25.11.nix) {};
 
     ### Set python version globally for the MMGen environment.
     ### Must be set if pkgs is set.