Pass the Python dict directly via the json= parameter of requests.request().

Let requests handle serialization and set the correct headers.

Author: wobrschalek

src/sysmlv2_client/client.py

@@ -44,7 +44,7 @@ def _request(
                 method=method,
                 url=url,
                 params=params,
-                data=json_data,
+                json=json_data,
             )
 
             # Check for specific error codes first