fix(api): remove static Content-Type header with wrong value on some …

…requests

The correct value is handled automatically by the requests library, only needed to be specified manually under specific circumstances

creatio_api_py/api.py

@@ -148,10 +148,7 @@ def _store_session_cookie(self, username: str) -> None:
 
     def _build_headers(self, endpoint: str, method: str) -> dict[str, str]:
         """Construct request headers."""
-        headers: dict[str, str] = {
-            "Content-Type": "application/json",
-            "ForceUseSession": "true",
-        }
+        headers: dict[str, str] = {"ForceUseSession": "true"}
 
         if "$metadata" not in endpoint:
             headers["Accept"] = "application/json; odata=verbose"