Rollup merge of #101898 - GuillaumeGomez:rm-unused-css, r=notriddle

Remove some unused CSS rules

Since we now have list of items for the ones on the page, we don't need the CSS rules anymore in the sidebar (`.sidebar a`). As for the `.content` ones, they are used to highlight the items in the page (for definitions and others). Surprisingly enough, `method` and `tymethod` are all replaced with `fnname`.

I also used this opportunity to remove these rules in `ayu.css`:

```css
.stab.unstable {}
h2,
h3:not(.impl):not(.method):not(.type):not(.tymethod), h4:not(.method):not(.type):not(.tymethod) {}
```

In the second commit, I removed the `.block a.current*` CSS rules as they're overridden by `.sidebar a.current*` CSS rules.

In the third commit I removed unneeded empty rules (that were there to satisfy the `--check-theme` option).

cc ``@jsha``
r? ``@notriddle``

0 files changed, 0 insertions, 0 deletions