fix (Azure#28652)

Author: msyyc

tools/azure-sdk-tools/packaging_tools/generate_utils.py

@@ -372,7 +372,7 @@ def gen_cadl(cadl_relative_path: str, spec_folder: str) -> Dict[str, Any]:
         with open("package.json", "r") as file_in:
             cadl_tools = json.load(file_in)
     else:
-        cadl_tools = {"dependencies:{}"}
+        cadl_tools = {"dependencies": dict()}
     cadl_tools["dependencies"].update(cadl_python_dep["dependencies"])
     with open("package.json", "w") as file_out:
         json.dump(cadl_tools, file_out)