Remove --wp-admin-theme-color reference from front-facing styles

[aristath]

The title says it all 😆

We recently introduced a new --wp-admin-theme-color CSS-variable.
That somehow stayed in the calendar block, so this PR removes it and the link can keep inheriting the theme's link styles.

[youknowriad]

👍 This is definitely not meant to be a frontend color.

Do you think how safe is it to just remove that rule, do we need to replace it with something else? What impacts this have on themes?

[aristath]

I don't think we need to replace it with something else... With the tfoot a rule missing, the link will simply inherit its color from normal links as it should.
Themes don't use the css-var for admin-theme-color schemes, and since that was only recently introduced the danger of any impact is practically zero. Coupled with the fact that the link will simply inherit its style from normal links this one should be OK 👍

[youknowriad]

Thanks for explaining further, it makes sense.