[MNT] Update setup list test assertion (#1652)

Fixes #1645

```
import openml

openml.config.server = "https://www.openml.org/api/v1/xml"
setups = openml.setups.list_setups(flow=5873)
```
<img width="334" height="201" alt="Screenshot 2026-02-18 at 7 12 32 PM"
src="https://github.com/user-attachments/assets/9efaca17-c3f4-4c41-aac9-3809062e9ced"
/>

Current number of setups is 2. 

> 1. For now, please keep using the production server for this test as
the test server is not guaranteed to have setups (yet)
> 2. Make the assertion based on a minimum. It is possible that people
upload more runs for the flow (and consequently, more setups). It is
also possible they delete them, but not so likely. So I would check a
lower bound that is lower than what is currently on the production
server.

cc @geetu040 @PGijsbers so should we use the lower bound as 1?  
```
assert len(setups) >= 1
```

Author: omkar-334

tests/test_setups/test_setup_functions.py

@@ -143,7 +143,7 @@ def test_setup_list_filter_flow(self):
 
         setups = openml.setups.list_setups(flow=flow_id)
 
-        assert len(setups) > 0  # TODO: please adjust 0
+        assert len(setups) >= 2
         for setup_id in setups:
             assert setups[setup_id].flow_id == flow_id