Sparse Vstack Op should not be a subclass of Hstack

This is a recipe for bug in rewrites. They should be distinct or inherit from a `Stack` baseclass that contains the common code

https://github.com/pymc-devs/pytensor/blob/d4a2b2bf037366fef8bead2e6a50f4bf2f49270e/pytensor/sparse/basic.py#L2902