Remove option to pass `normal_direction_avg` for `NonConservativeJump` terms

> @amrueda To prevent this problem in the future, should we just remove the option to pass the averaged normal direction to the `NonConservativeJump` part in [ `calcflux_fhat!`](https://github.com/patrickersing/Trixi.jl/blob/059ddccb80c7accfeb68c90ece4a856daf579e6c/src/solvers/dgsem_structured/dg_2d_subcell_limiters.jl#L383)? That's a good point. In general, I don't think that we'll ever want to pass the averaged normal direction to the `NonConservativeJump` part. However, we might want to pass `Ja_ll` and `Ja_rr` in the future(?) 🤔 I.e., we either pass no normal direction or we pass the two. I suggest we just remove the normal direction argument in that routine for the time being. If we ever realize we need the two directions in the future, we can create a new PR. _Originally posted by @amrueda in https://github.com/trixi-framework/TrixiShallowWater.jl/issues/131#issuecomment-4022098424_