Remove unnecessary padding-right on the dismissible notice

[kmanijak]

What?

In this PR I removed the padding-right from a Notice component when it's dismissable.

Why?

When Notice was dismissable, an additional 36px padding-right was applied to the Notice container, pushing the content to the left, which makes little space for Notice content especially when used in Inspector Controls. It seems incorrect on the frontend (see screenshots below).

Worth to mention that the "X" button is coincidentally 36px wide, so the original idea might've been to apply the padding so the content makes space for an "X" button, but now it pushes both: "X" button and content.

How?

It's fixed by removing the unnecessary padding-right from the .components-notice.is-dismissable selector.

Testing Instructions

1. Edit some block Inspector Controls by including:

import { Notice } from '@wordpress/components';

...

<Notice>
    Some content of the Notice. Make sure it's wide enough to fill available space.
</Notice>

Notice component is dismissable by default, so there's no need to pass any additional props to it.
2. Display the Notice in the frontend
3. Expected: There's no unnecessary gap on the right side (check screenshots below).

Screenshots or screencast

Before	After

[jorgefilipecosta]

Hi @kmanijak, thank you for this fix. I think it makes sense to apply this fix and not change padding when the notice is dismissible. If needed users of the component can style it and change for example notices related to post saving falling already change the padding.