Tweak highlighting when trait is available for different type

When printing

```
  = help: the trait `chumsky::private::ParserSealed<'_, &'a str, ((), ()), chumsky::extra::Full<EmptyErr, (), ()>>` is implemented for `Then<Ignored<chumsky::combinator::Filter<chumsky::primitive::Any<&str, chumsky::extra::Full<EmptyErr, (), ()>>, {closure@src/main.rs:9:17: 9:27}>, char>, chumsky::combinator::Map<impl CSTParser<'a, O>, O, {closure@src/main.rs:11:24: 11:27}>, (), (), chumsky::extra::Full<EmptyErr, (), ()>>`
  = help: for that trait implementation, expected `((), ())`, found `()`
```

Highlight only the `expected` and `found` types, instead of the full type in the first `help`.

1 files changed, 2 insertions, 2 deletions

diff --git a/tests/ui/impl-trait/diagnostics/highlight-difference-between-expected-trait-and-found-trait.svg b/tests/ui/impl-trait/diagnostics/highlight-difference-between-expected-trait-and-found-trait.svg
index aaf08b9a246..e09b96e5ff2 100644
--- a/tests/ui/impl-trait/diagnostics/highlight-difference-between-expected-trait-and-found-trait.svg
+++ b/tests/ui/impl-trait/diagnostics/highlight-difference-between-expected-trait-and-found-trait.svg
@@ -33,9 +33,9 @@
 </tspan>
     <tspan x="10px" y="118px"><tspan>   </tspan><tspan class="fg-ansi256-012 bold">|</tspan>
 </tspan>
-    <tspan x="10px" y="136px"><tspan>   </tspan><tspan class="fg-ansi256-012 bold">= </tspan><tspan class="bold">help</tspan><tspan>: the trait `Bar&lt;()&gt;` </tspan><tspan class="fg-magenta bold">is</tspan><tspan> implemented for `</tspan><tspan class="fg-magenta bold">Struct</tspan><tspan>`</tspan>
+    <tspan x="10px" y="136px"><tspan>   </tspan><tspan class="fg-ansi256-012 bold">= </tspan><tspan class="bold">help</tspan><tspan>: the trait `Bar&lt;()&gt;` </tspan><tspan class="fg-magenta bold">is</tspan><tspan> implemented for `Struct`</tspan>
 </tspan>
-    <tspan x="10px" y="154px"><tspan>   </tspan><tspan class="fg-ansi256-012 bold">= </tspan><tspan class="bold">help</tspan><tspan>: for that trait implementation, expected `()`, found `i32`</tspan>
+    <tspan x="10px" y="154px"><tspan>   </tspan><tspan class="fg-ansi256-012 bold">= </tspan><tspan class="bold">help</tspan><tspan>: for that trait implementation, expected `</tspan><tspan class="fg-magenta bold">()</tspan><tspan>`, found `</tspan><tspan class="fg-magenta bold">i32</tspan><tspan>`</tspan>
 </tspan>
     <tspan x="10px" y="172px"><tspan class="fg-ansi256-010 bold">note</tspan><tspan>: required for `Struct` to implement `Foo&lt;i32&gt;`</tspan>
 </tspan>