refactor(flake): Update Flake usage to avoid Nix warnings

Author: alerque

flake.nix

@@ -12,41 +12,31 @@
       cargoToml = (builtins.fromTOML (builtins.readFile ./Cargo.toml));
       supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" ];
       forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f system);
+      pkgsFor = forAllSystems (system:
+        import nixpkgs {
+          inherit system;
+          overlays = [ self.overlays.default ];
+        });
     in
     {
       overlays.default = final: prev: {
         "${cargoToml.package.name}" = final.callPackage ./. { inherit naersk; };
       };
-      packages = forAllSystems (system:
+      packages = forAllSystems (system: {
+        default = pkgsFor.${system}.${cargoToml.package.name};
+        ${cargoToml.package.name} = pkgsFor.${system}.${cargoToml.package.name};
+      });
+      devShells = forAllSystems (system:
         let
-          pkgs = import nixpkgs {
-            inherit system;
-            overlays = [
-              self.overlays.default
-            ];
-          };
+          pkgs = pkgsFor.${system};
         in
         {
-          "${cargoToml.package.name}" = pkgs."${cargoToml.package.name}";
-        });
-      defaultPackage = forAllSystems (system: (import nixpkgs {
-        inherit system;
-        overlays = [ self.overlays.default ];
-      })."${cargoToml.package.name}");
-      devShell = forAllSystems (system:
-        let
-          pkgs = import nixpkgs {
-            inherit system;
-            overlays = [ self.overlays.default ];
+          default = pkgs.mkShell {
+            inputsFrom = [ pkgs.${cargoToml.package.name} ];
+            buildInputs = with pkgs; [
+              libgit2
+            ];
           };
-        in
-        pkgs.mkShell {
-          inputsFrom = with pkgs; [
-            pkgs."${cargoToml.package.name}"
-          ];
-          buildInputs = with pkgs; [
-            libgit2
-          ];
         });
     };
 }