Styled export no longer works for adopters

[silvalaura]

We recently updated our styled imports: https://github.com/cengage/react-magma/commit/c1ef7d0cb94b1068d0b5fe237b901a6bba839a66 as a result of failing builds. This works fine internally within Magma, but our consumers are also expecting to import styled from our package and that no longer works.

This can be tested by reverting this PR: https://github.com/cengage/react-magma/pull/1313 and also confirming on CodeSandbox.

Notes:

• See https://github.com/cengage/react-magma/blob/dev/packages/react-magma-dom/src/theme/styled.ts