[Feature request] Brand Img Alt Text

[nruffing]

Clear and concise description of the problem

Dequeue/Axe recommends not to include alt text on an image that is also already displayed next to it. A screen reader will then read it twice.
https://dequeuniversity.com/rules/axe/4.8/image-redundant-alt?application=AxeChrome

Currently the brand image in the default theme will also use the site title it displays as the alt text of the brand image.

Suggested solution

I think we should add a theme option to specify the brand image alt text and default it to an empty string but still render the attribute like Dequeue recommends.

We will also need to make sure this works appropriately with screen readers when in a mobile resolution where the brand image is displayed but the title is hidden.

Alternative

No response

Additional context

No response