increase client timeout to 60 minutes (#198)

### Notes
Increased the default timeout for partition calls to 60 minutes.

src/unstructured_client/_hooks/custom/split_pdf_hook.py

@@ -275,7 +275,7 @@ def before_request(
         # Use a variable to adjust the httpx client timeout, or default to 30 minutes
         # When we're able to reuse the SDK to make these calls, we can remove this var
         # The SDK timeout will be controlled by parameter
-        client_timeout_minutes = 30
+        client_timeout_minutes = 60
         if timeout_var := os.getenv("UNSTRUCTURED_CLIENT_TIMEOUT_MINUTES"):
             client_timeout_minutes = int(timeout_var)