Allow PrettyVersion 2

[Jean85]

Q	A
Type	improvement
BC Break	no
Fixed issues	None

Summary

This simple bump allows for the 2.0 version of this lib, which leverages Composer 2 APIs and drops any sub dependency.

There are basically no BC; for more details, see the the changelog.

This could be easily cherry-picked in the 2.0 and 2.1 branches if needed.

[malarzm]

Thanks a lot @Jean85!

[IonBazan]

@malarzm I think this change was not merged into 2.2.x branch: https://github.com/doctrine/mongodb-odm/blob/2.2.1/composer.json but was mentioned in release notes: https://github.com/doctrine/mongodb-odm/releases/tag/2.2.1 Can you cherry-pick it and merge into 2.2.x and maybe some older branches too?

[alcaeus]

You are correct, this PR incorrectly used the 2.2.1 milestone despite going into the 2.3.x branch today (then still called master). I'm hesitant to backport this now, especially with the release of 2.3 imminent (just waiting to wrap up #2238 and #2308 here as well as a bundle change).