configure_controller error path causes controller manager to hang for invalid chainable controllers

[Anusha-Sharma-2]

Describe the bug
When configuring a chainable controller that does not export any state or reference interfaces, configure_controller() returns ERROR as expected, but the controller manager does not terminate cleanly and remains active, causing tests or processes to hang indefinitely.

To Reproduce
Steps to reproduce the behavior:

1. Create a chainable controller that exports no state or reference interfaces
2. Add it to the controller manager
3. Initialize the resource manager
4. Call configure_controller
5. Observe that ERROR is returned and logged correctly, however the process/test does not terminate and hangs unless interrupted

Example:

// Minimal reproduction (adapted from existing test patterns)
auto bad_controller =
  std::make_shared<test_chainable_controller::TestChainableController>();

cm_->add_controller(
  bad_controller,
  "bad_chainable_controller",
  test_chainable_controller::TEST_CONTROLLER_CLASS_NAME);

pass_robot_description_to_cm_and_rm();

auto ret = cm_->configure_controller("bad_chainable_controller");

Expected: ERROR
Actual: returns ERROR but system does not terminate cleanly

Expected behavior
After returning ERROR, the controller manager should:

• fully exit or roll back the configuration lifecycle transition
• not leave the system in an active/spinning state
• allow tests or processes to terminate normally

Screenshots
N/A (logs below)

[INFO] Configuring controller: 'bad_chainable_controller'
[ERROR] Controller 'bad_chainable_controller' is chainable, but does not export any state or reference interfaces
(hangs)

Environment (please complete the following information):

• OS: Ubuntu 24.04
• ROS 2 Version: Rolling
• Workspace: local build of ros2_control
• No modifications to core logic (issue observed while adding test coverage)

Additional context
Add any other context about the problem here, especially include any modifications to ros2_control that relate to this issue.