Fix Python E2E agent list test for built-in agents

The CLI now returns built-in/default agents even when no custom agents
are configured. Update the assertion to verify no custom test agent
names appear in the list, rather than asserting the list is empty.
Matches the pattern used in the Go E2E test.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 2 people

python/e2e/test_agent_and_compact_rpc.py

@@ -147,7 +147,7 @@ async def test_should_deselect_current_agent(self):
 
     @pytest.mark.asyncio
     async def test_should_return_empty_list_when_no_custom_agents_configured(self):
-        """Test listing agents returns empty when none configured."""
+        """Test listing agents returns no custom agents when none configured."""
         client = CopilotClient(SubprocessConfig(cli_path=CLI_PATH, use_stdio=True))
 
         try:
@@ -157,7 +157,13 @@ async def test_should_return_empty_list_when_no_custom_agents_configured(self):
             )
 
             result = await session.rpc.agent.list()
-            assert result.agents == []
+            # The CLI may return built-in/default agents even when no custom agents
+            # are configured. Verify no custom test agents appear in the list.
+            custom_names = {"test-agent", "another-agent"}
+            for agent in result.agents:
+                assert agent.name not in custom_names, (
+                    f"Expected no custom agents, but found {agent.name!r}"
+                )
 
             await session.disconnect()
             await client.stop()