Improve Site Logo Background in Editor for Better Visibility

[morivishal]

When editing a post/page in the block editor, the Site Logo in the top left corner currently has a solid black background. This causes visibility issues when the site logo itself contains black or dark elements, as the logo blends into the background and becomes difficult to distinguish.

For example this logo

Proposed Solution:
We can make the background transparent so that the logo is always visible in its true form.

[hanneslsm]

Thank you for the report.
I close this issue in favor of #49501
Please feel free to contribute there by adding comments and reviewing the open PR.