After the next feature release of TraitsUI, we want to remove the [conditional imports](https://github.com/enthought/traits/blob/9e07f009a18733ce0ec8c848b8429c9a0b5f5c07/traits/api.py#L229-L238) of TraitsUI from `traits.api`.
After the next feature release of TraitsUI, we want to remove the conditional imports of TraitsUI from
traits.api.