Remove unneeded 'static lifetimes on &strs in constants (#8698)

This PR removes unneeded `'static` lifetimes on `&str`s stored in
`const` declarations.

This addresses some Clippy lints about
[`redundant_static_lifetimes`](https://rust-lang.github.io/rust-clippy/master/index.html#/redundant_static_lifetimes).

In item-level `const` declarations we can rely on lifetime elision and
use the default `'static` lifetime.

Note that associated constants still require an explicit `'static`
lifetime, as explained in
https://github.com/rust-lang/rust/issues/115010.

Release Notes:

- N/A

crates/ui/src/components/stories/list_item.rs

@@ -4,7 +4,7 @@ use story::Story;
 use crate::{prelude::*, Avatar};
 use crate::{IconName, ListItem};
 
-const OVERFLOWING_TEXT: &'static str = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean mauris ligula, luctus vel dignissim eu, vestibulum sed libero. Sed at convallis velit.";
+const OVERFLOWING_TEXT: &str = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean mauris ligula, luctus vel dignissim eu, vestibulum sed libero. Sed at convallis velit.";
 
 pub struct ListItemStory;