Casting complex values to reals when applying Controlled Gates in Lightning-Kokkos

[maliasadi]

Issue description

Applying controlled gates in Lightning-Kokkos will raise ComplexWarnings complaining about some unnecessary casting complex values to real:

@qml.qnode(qml.device("lightning.kokkos", wires=4))
def circuit():
    qml.PauliZ(0)
    qml.ctrl(qml.PauliZ(0), control=[1,2,3])
    return qml.probs()

>>> circuit()
./pennylane_lightning/lightning_kokkos/_state_vector.py:204: ComplexWarning: Casting complex values to real discards the imaginary part

• System information:

Name: PennyLane
Version: 0.38.0
Required-by: PennyLane-qiskit, PennyLane_Lightning, PennyLane_Lightning_Kokkos, qml_benchmarks

Platform info:           Linux-6.8.0-45-generic-x86_64-with-glibc2.35
Python version:          3.11.8
Numpy version:           1.26.4
Scipy version:           1.14.1
Installed devices:
- lightning.qubit (PennyLane_Lightning-0.39.0.dev40)
- lightning.kokkos (PennyLane_Lightning_Kokkos-0.39.0.dev40)
- default.mixed (PennyLane-0.38.0)
- default.qubit (PennyLane-0.38.0)