Please upgrade to use `decimal: ^3.1.0`

[RoarGronmo]

Have som dependencies that breaks on:

Because no versions of flutter_charts match >0.5.2 <0.6.0 and flutter_charts 0.5.2 depends on decimal ^2.1.0, flutter_charts ^0.5.2 requires decimal ^2.1.0.
And because flutter_resizable_container >=4.0.0-beta.4 depends on decimal ^3.1.0, flutter_charts ^0.5.2 is incompatible with flutter_resizable_container >=4.0.0-beta.4.
So, because m_portal depends on both flutter_resizable_container ^4.0.0 and flutter_charts ^0.5.2, version solving failed.

Can you please upgrade to use decimal: ^3.1.0 or more.