Rollup merge of rust-lang#101554 - notriddle:notriddle/implemenation-list-h3-span-in-band, r=Dylan-DPC

rustdoc: remove unused CSS `#implementations-list > h3 > span.in-band`

This was added in 51f26ac to help with the display of an `<h3>` tag that has a `<span class='in-band'>` inside.

The way implementation lists were rendered was changed in 34bd2b8 to have `<code class='in-band'>`, making this CSS unused.

Then it was turned into a `<div>` in 9077d54 without issue.

Finally, the header itself acquired the `in-band` class in 76a3b60.

Author: compiler-errors

src/librustdoc/html/static/css/rustdoc.css

@@ -1528,10 +1528,6 @@ kbd {
 	cursor: default;
 }
 
-#implementations-list > h3 > span.in-band {
-	width: 100%;
-}
-
 #main-content > ul {
 	padding-left: 10px;
 }