Update dio dependency to 4.0.0

[DenisBogatirov]

Current version of transformer forces use of 3.x.x version of dio

Because dio_flutter_transformer >=3.0.0 depends on dio ^3.0.0 and PROJECT depends on dio ^4.0.0, dio_flutter_transformer >=3.0.0 is forbidden.
So, because PROJECT depends on dio_flutter_transformer ^3.0.2, version solving failed.
pub get failed (1; So, because PROJECT depends on dio_flutter_transformer ^3.0.2, version solving failed.)

[baseSky]

有解决吗？