style(mcp): apply autoformat to fix lint errors

- Format mcp_session_manager.py (remove unnecessary f-string prefix)
- Format test_mcp_session_manager.py (consolidate pytest.raises call)

Author: raben

src/google/adk/tools/mcp_tool/mcp_session_manager.py

@@ -378,7 +378,7 @@ async def create_session(
               'Error during cancelled session cleanup: %s', exit_stack_error
           )
         raise ConnectionError(
-            f'MCP session creation cancelled (server may have returned HTTP'
+            'MCP session creation cancelled (server may have returned HTTP'
             f' error): {e}'
         ) from e
 

tests/unittests/tools/mcp_tool/test_mcp_session_manager.py

@@ -316,9 +316,7 @@ async def test_create_session_cancelled_error(
     )
 
     # Expect ConnectionError due to CancelledError
-    with pytest.raises(
-        ConnectionError, match="MCP session creation cancelled"
-    ):
+    with pytest.raises(ConnectionError, match="MCP session creation cancelled"):
       await manager.create_session()
 
     # Verify session was not added to pool