switch from import to callPackage in nix

flake.nix

@@ -14,7 +14,7 @@
       system: let
         pkgs = pkgsForEach.${system};
       in rec {
-        osuplusplus = import ./nix/shell.nix {inherit pkgs;};
+        osuplusplus = pkgs.callPackage ./nix/shell.nix {};
         default = osuplusplus;
       }
     );
@@ -22,7 +22,7 @@
       system: let
         pkgs = pkgsForEach.${system};
       in rec {
-        osuplusplus = import ./nix/default.nix {inherit (pkgs) lib stdenv sfml;};
+        osuplusplus = pkgs.callPackage ./nix/default.nix {};
         default = osuplusplus;
       }
     );

nix/shell.nix

@@ -1,15 +1,22 @@
-{pkgs}:
-pkgs.mkShell {
+{
+  mkShell,
+  gcc,
+  gnumake,
+  clang-tools,
+  sfml,
+  ...
+}:
+mkShell {
   name = "osu++";
 
-  nativeBuildInputs = with pkgs; [
+  nativeBuildInputs = [
     gcc
     gnumake
     # for clang-format
     clang-tools
   ];
 
-  buildInputs = with pkgs; [
+  buildInputs = [
     sfml
   ];
 }