[Bug: Spinner] Spinner cannot be vertically aligned properly due to descender on span

[LA1CH3]

Summary

See this comment (https://github.com/Shopify/web/pull/122620#discussion_r1552204022).

If Spinner is used in a flex row with other components, and align-items: center is applied, the Spinner is not quite vertically centered.

The root of the issue lies in the Polaris spinner component, which is wrapped in a span. This makes it an inline element and introduces additional bottom spacing reserved for descenders. As a result, even though the flex container wrapping all buttons is set to center alignment, it doesn't properly align the spinner due to the extra whitespace inherent to the spinner element.

Expected behavior

The Spinner is vertically aligned as expected.

Actual behavior

Steps to reproduce

Link to sandbox

Are you using React components?

Yes

Polaris version number

"12.26.0"

Browser

Latest Chrome

Device

Macbook pro