[maliasadi]

Context:

lightning.cliffish is a planned near-Clifford simulator in pennylane-lightning that runs only through qp.qjit(capture=True).

Description of the Change:

• New opt-in test runner, runner_tests_lightning_cliffish, built only when
  LIGHTNING_CLIFFISH_LIB names the device library:

  make -C runtime test LIGHTNING_CLIFFISH_LIB=/path/to/liblightning_cliffish_catalyst.so

Benefits:

• Runtime changes made for lightning.cliffish can be tested locally against the device itself.
• Without LIGHTNING_CLIFFISH_LIB, the runtime build and test suite are unchanged.

pennylane-lightning backend and device: PennyLaneAI/pennylane-lightning#1433

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This PR was prepared with the assistance of AI. I have reviewed the code and tested it locally.