fix(react): remove incorrect class key from IonicReactProps (#27432)

Issue number: N/A

---------

<!-- Please do not submit updates to dependencies unless it fixes an
issue. -->

<!-- Please try to limit your pull request to one type (bugfix, feature,
etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

As noted in https://github.com/ionic-team/ionic-framework/issues/27415,
`IonicReactProps` still has `class` as an exposed attribute on Ionic
React components. React components should use the `className` property
instead. It looks like this was left over code from the Ionic React beta
that never got removed.

`class` was originally added in
https://github.com/ionic-team/ionic-framework/commit/c79e74b91fdfd931f7ae082cfc374b2e55ee6d06#diff-065219c56a8c5dfc32564fac317b8cc9c03f1fbcb7f9cc2de0c5581970f21b51

And `className` was added in
https://github.com/ionic-team/ionic-framework/commit/ab0f92e01f892c1c5f0db6e1e8467fe553e48bdd#diff-065219c56a8c5dfc32564fac317b8cc9c03f1fbcb7f9cc2de0c5581970f21b51

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- Removes the `class` key

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!-- If this introduces a breaking change, please describe the impact
and migration path for existing applications below. -->


## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->