nix: switch to shell.nix instead of flakes

.envrc

@@ -1 +1 @@
-use flake
+use nix

flake.lock

@@ -1,27 +0,0 @@
-{
-  "nodes": {
-    "nixpkgs": {
-      "locked": {
-        "lastModified": 1773821835,
-        "narHash": "sha256-TJ3lSQtW0E2JrznGVm8hOQGVpXjJyXY2guAxku2O9A4=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "b40629efe5d6ec48dd1efba650c797ddbd39ace0",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-unstable",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
-    "root": {
-      "inputs": {
-        "nixpkgs": "nixpkgs"
-      }
-    }
-  },
-  "root": "root",
-  "version": 7
-}

flake.nix

@@ -1,31 +0,0 @@
-{
-  description = "Rust dev flake";
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
-  };
-  outputs = {
-    self,
-    nixpkgs,
-  }: let
-    system = "x86_64-linux";
-    pkgs = import nixpkgs {inherit system;};
-  in {
-    devShells."x86_64-linux".default = pkgs.mkShell {
-      nativeBuildInputs = with pkgs; [
-      ];
-      buildInputs = with pkgs; [
-        rustc
-        rust-analyzer
-        rustfmt
-        clippy
-        cargo
-        cargo-watch
-      ];
-      shellHook = ''
-        echo "========================================================="
-        echo "Pour lancer le projet et avoir les changements en temps réel : "
-        echo "- cargo watch -w content -w src -w templates -w static -x run"
-      '';
-    };
-  };
-}

shell.nix

@@ -0,0 +1,17 @@
+{pkgs ? import <nixpkgs> {}}:
+pkgs.mkShell {
+  packages = with pkgs; [
+    rustc
+    rust-analyzer
+    rustfmt
+    clippy
+    cargo
+    cargo-watch
+  ];
+
+  shellHook = ''
+    echo "========================================================="
+    echo "Pour lancer le projet et avoir les changements en temps réel : "
+    echo "- cargo watch -w content -w src -w templates -w static -x run"
+  '';
+}