fix: use platform.uname() instead of os.uname() so it works across platforms

Author: christyjacob4

templates/python/package/client.py.twig

@@ -1,6 +1,7 @@
 import io
 import json
 import os
+import platform
 import requests
 from .input_file import InputFile
 from .exception import {{spec.title | caseUcfirst}}Exception
@@ -13,7 +14,7 @@ class Client:
         self._endpoint = '{{spec.endpoint}}'
         self._global_headers = {
             'content-type': '',
-            'user-agent' : f'{{spec.title | caseUcfirst}}{{ language.name | caseUcfirst }}SDK/{{ sdk.version }} ({os.uname().sysname}; {os.uname().version}; {os.uname().machine})',
+            'user-agent' : f'{{spec.title | caseUcfirst}}{{ language.name | caseUcfirst }}SDK/{{ sdk.version }} ({platform.uname().system}; {platform.uname().version}; {platform.uname().machine})',
             'x-sdk-name': '{{ sdk.name }}',
             'x-sdk-platform': '{{ sdk.platform }}',
             'x-sdk-language': '{{ language.name | caseLower }}',