CompatHelper: bump compat for OrderedCollections to 2, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the OrderedCollections package from 1 to 1, 2.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[kalidke]

Holding off on merging this for now: the widened compat is unsatisfiable in the current ecosystem — DataStructures (our direct dep, compat 0.18.20, 0.19) restricts OrderedCollections to 1.1.0 - 1.8.2 across all its published versions, so no resolvable graph can actually exercise OrderedCollections 2 with this package:

restricted by compatibility requirements with DataStructures [864edb3b] to versions: 1.1.0 - 1.8.2 — no versions left

Merging now would ship a compat claim we cannot test, which would silently activate the moment DataStructures widens. Leaving this open; once a DataStructures release supports OrderedCollections 2 we can resolve, run the full suite (our usage surface is LittleDict throughout serialization), and merge.