fix: fix the error about options not set when disabling the devShell or package options for templates

rust/default.nix

@@ -135,15 +135,18 @@
           # Dev Shell that lets you enter an environment with all the necessary utilites
           # Available through 'nix develop'
           # Also can be activated automatically if direnv is installed on the system with 'direnv allow'
-          devShells.${cfg.devShell.name} = lib.mkIf cfg.devShell.enable (craneLib.devShell {
-              inherit (self') checks;
+          devShells = lib.mkIf cfg.devShell.enable {
+            ${cfg.devShell.name} =
+              craneLib.devShell {
+                inherit (self') checks;
 
-              # extra tooling dependencies
-              packages = cfg.devDeps;
+                # extra tooling dependencies
+                packages = cfg.devDeps;
 
-              inputsFrom = [self'.packages.${cfg.package.name}];
-            }
-            // cfg.devShell.extraAttrs);
+                inputsFrom = [self'.packages.${cfg.package.name}];
+              }
+              // cfg.devShell.extraAttrs;
+          };
 
           # Formatter for nix files, available through 'nix fmt'
           treefmt = {
@@ -156,10 +159,13 @@
 
           # Your custom packages
           # Accessible through 'nix build', 'nix shell', 'nix run', etc
-          packages.${cfg.package.name} = lib.mkIf cfg.package.enable (craneLib.buildPackage {
-              inherit src buildInputs nativeBuildInputs cargoArtifacts;
-            }
-            // cfg.package.extraAttrs);
+          packages = lib.mkIf cfg.package.enable {
+            ${cfg.package.name} =
+              craneLib.buildPackage {
+                inherit src buildInputs nativeBuildInputs cargoArtifacts;
+              }
+              // cfg.package.extraAttrs;
+          };
 
           checks = {
             clippy = craneLib.cargoClippy {