Remove custom outline button styles

[richtabor]

We should use theme.json to style variations instead. Otherwise it complicates how styles are accounted for.

.wp-block-button.is-style-outline
	> .wp-block-button__link:not(.has-text-color, .has-background):hover {
	background-color: var(--wp--preset--color--contrast, transparent);
	color: var(--wp--preset--color--base);
	border-color: var(--wp--preset--color--contrast, currentColor);
}

[carolinan]

Yes this is in progress.

[carolinan]

I think this is part of #414. / #407

[richtabor]

I'm questioning if this is necessary to include as a separate stylesheet here. If we're ok accepting the complexity with this.