Rollup merge of #53706 - ehuss:rustdoc-section-anchor, r=GuillaumeGomez
Rollup merge of #53706 - ehuss:rustdoc-section-anchor, r=GuillaumeGomez

rustdoc: Fix gap on section anchor symbol when hovering.

Fixes #49485 for section headings.

aidancully/rust,graydon/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,GBGamer/rust,GBGamer/rust,graydon/rust,GBGamer/rust,GBGamer/rust,graydon/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust