Cannot upgrade rxdart to latest

[mulderpf]

🔙 Regression

Old (and correct) behavior

I was able to use the latest version of rxdart together with flutter_cache_manager

Current behavior

When I update rxdart to the latest package, I get the following issue:
`Resolving dependencies...
Because flutter_cache_manager 3.3.2 depends on rxdart ^0.27.7 and no versions of flutter_cache_manager match >3.3.2 <4.0.0, flutter_cache_manager ^3.3.2 requires rxdart ^0.27.7.
So, because LondonBusPal depends on both flutter_cache_manager ^3.3.2 and rxdart ^0.28.0, version solving failed.

You can try the following suggestion to make the pubspec resolve:

• Consider downgrading your constraint on rxdart: flutter pub add rxdart:^0.27.7
  exit code 1`

Reproduction steps

Update rxdart to version 0.28.0

[renefloor]

Fixed in flutter_cache_manager: ^3.3.3