Flake: better dependency management

flake.lock

@@ -286,7 +286,7 @@
     "home-manager": {
       "inputs": {
         "nixpkgs": [
-          "nixpkgs"
+          "nixpkgs-s"
         ]
       },
       "locked": {
@@ -498,6 +498,22 @@
         "type": "github"
       }
     },
+    "nixpkgs-s": {
+      "locked": {
+        "lastModified": 1749906907,
+        "narHash": "sha256-3utRKKFaoVhanwUqzb2fCnTcskq2uwSCDD/zLgnSa/E=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "200b75e8120c5bbe749f600f4e24d405a9bc8633",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "release-25.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "nixpkgs-u": {
       "locked": {
         "lastModified": 1748693115,
@@ -545,22 +561,6 @@
         "type": "github"
       }
     },
-    "nixpkgs_4": {
-      "locked": {
-        "lastModified": 1748954775,
-        "narHash": "sha256-9yZojiHsS+Bi9OivZglSIXryy6iCJZfM8UMn59tiKc8=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "667858166b89c072208ac151fa9502513d7d8389",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "release-24.11",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
     "ragenix": {
       "inputs": {
         "agenix": "agenix",
@@ -596,7 +596,10 @@
         "nix-rice": "nix-rice",
         "nixos-generators": "nixos-generators",
         "nixos-hardware": "nixos-hardware",
-        "nixpkgs": "nixpkgs_4",
+        "nixpkgs": [
+          "nixpkgs-u"
+        ],
+        "nixpkgs-s": "nixpkgs-s",
         "nixpkgs-u": "nixpkgs-u",
         "ragenix": "ragenix",
         "systems": "systems_5"