Simplify UnsafePointer function signatures.

Remove all usage of alignment and address_space from function signatures since bitcast already has those options:

    fn bitcast[
        T: AnyType = Self.type,
        /,
        address_space: AddressSpace = Self.address_space,
        alignment: Int = Self.alignment,
        origin: Origin[True].type = Self.origin,
    ](self) -> UnsafePointer[T, address_space, alignment, origin]:
    ...

This might break a lot of Modular internal code. Since we don't have a deprecation warning that can be tuned to specific args or parameters, I went for just deleting the parameters. We could also duplicate the function signatures and add @deprecated to those with alignment and/or address_space options.