Inline all format arguments where possible

This makes code more readale and concise,
moving all format arguments like `format!("{}", foo)`
into the more compact `format!("{foo}")` form.

The change was automatically created with, so there are far less change
of an accidental typo.

```
cargo clippy --fix -- -A clippy::all -W clippy::uninlined_format_args
```

crates/ide-completion/src/tests/pattern.rs

@@ -9,7 +9,7 @@ fn check_empty(ra_fixture: &str, expect: Expect) {
 }
 
 fn check(ra_fixture: &str, expect: Expect) {
-    let actual = completion_list(&format!("{}\n{}", BASE_ITEMS_FIXTURE, ra_fixture));
+    let actual = completion_list(&format!("{BASE_ITEMS_FIXTURE}\n{ra_fixture}"));
     expect.assert_eq(&actual)
 }