Remove long deprecated `AllPalletsWithoutSystemReversed` (#2509)

Remove deprecated `AllPalletsXY` types.

They have been deprecated for nearly 1.5 years now, I think its fine to
remove them.
If anyone feels like we should first put a date on the deprecation as
stated in the deprecation guideline, feel free to speak up. To me it
looks like this has been forgotten and can be directly removed.