`to_power_type` does not exist any more in `Base`

The `to_power_type` function doesn't exist any more in Julia `Base` since PR https://github.com/JuliaLang/julia/pull/58720. I suppose that will break loading of this package because of:

https://github.com/JuliaArrays/LazyArrays.jl/blob/5ab3edd08baa0dcfdf0af9aef90934eb9120ef28/src/LazyArrays.jl#L62