Resolve "Images in Wiki display have wrong size"

What does this MR do?

Resets the min-width/max-height/background that is used as a placeholder in the content. Used wrongly none keyword instead of inherit.

Before :

After :

Why was this MR needed?

Otherwise the content images are using the min sizes and are huge

Screenshots (if relevant)

See issue

Does this MR meet the acceptance criteria?

• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #35691 (closed)