Several people have put forward answers where the pulse propagates for a long time, but not indefinitely.
- A pulse with self-induced transparency still eventually decays, due to scattering and absorptive losses.
- A soliton still eventually decays, due to scattering and absorptive losses.
- Stopped light still eventually decays, because the atoms will eventually lose their coherence due to random environmental perturbations.
If that's what you're interested in, there's a much less exotic and more practical way to do it: Fiber optics. A light pulse will pass through many kilometers of a fiber optic cable before appreciably decaying. A loop of fiber optic will store a pulse for a while (but not forever). There are a variety of dispersion-compensation technologies if you're worried about maintaining the shape of the pulse with high fidelity. (Using soliton pulses is one such technology but not the only one.)
If you want the pulse to last forever, you need to feed new energy into it to compensate for the losses. For example, a laser cavity will maintain light inside it forever, as long as you keep the laser's pump turned on. Ditto a loop of fiber optic with an erbium-doped fiber amplifier in the loop.
None of this is at all analogous to superconductivity. It's analogous to high-but-not-infinite-conductivity wire.