Issue number: N/A

What is the current behavior?

The Datetime component breaks CSP rules due to the following:

1. Datetime is using ion-buttons which uses scoped encapsulation.
2. When using the ionic theme, it imports Phosphor icons as data URIs, which are blocked by connect-src 'self' blob:.

What is the new behavior?

• Remove all usages of ion-buttons, removing the dependency on a scoped component
• Updates the styling to account for the removal of ion-buttons
• Updates ion-button to change its styles based on being inside of an ion-datetime

Phosphor icons have not been removed because there is a workaround for it and we will remove its usage across all components in future work.

Does this introduce a breaking change?

• Yes
• No

This shouldn't cause breaking changes but because we are no longer recommending users use ion-buttons with custom buttons I am marking it as a breaking change.

BREAKING CHANGE:

- The `ion-buttons` component has been removed from the internal implementation of `ion-datetime` and is no longer required when passing custom buttons to the `slot="buttons"`. When providing custom buttons, use a `div` element instead of `ion-buttons`. While existing code using `ion-buttons` may continue to work visually, future updates to the `ion-buttons` component may cause any styles you rely on to break.