[Bug]: sp-progress-circle over-background doesn't render properly within a button

[adixon-adobe]

Code of conduct

• [X] I agree to follow this project's code of conduct.

Impacted component(s)

sp-button, sp-progress-circle

Expected behavior

You should be able to use a progress circle within the icon slot of a button.

Actual behavior

In the dark theme, the background and progress both render white, like in this example: https://studio.webcomponents.dev/edit/Ielqz00YFXN0rQVpIc2u

Screenshots

What browsers are you seeing the problem in?

No response

How can we reproduce this issue?

Via this example: https://studio.webcomponents.dev/edit/Ielqz00YFXN0rQVpIc2u

Sample code that illustrates the problem

No response

Logs taken while reproducing problem

No response

[adixon-adobe]

I also see an issue with <sp-button variant="black"> in the light theme that I don't see in the doc pages, so might be worth checking the latest SWC version (not sure how to ensure that in the webcomponents.dev).