fix: correct suggestion for significant_drop_in_scrutinee in expressions (#14019)

This PR fixes an issue with the `significant_drop_in_scrutinee`, where
the lint generates invalid Rust syntax when suggesting fixes for match
expressions that are part of larger expressions, such as in assignment
contexts. For example:

```rust
    let mutex = Mutex::new(State {});
    let _ = match mutex.lock().unwrap().foo() {
        true => 0,
        false => 1,
    };
```
would suggest:
```rust
let _ = let value = mutex.lock().unwrap().foo();
match value {
```
With this PR, it now suggests:
```rust
let value = mutex.lock().unwrap().foo();
let _ = match value {
```

closes: #13986

changelog: [`significant_drop_in_scrutinee`] Fix incorrect suggestion
for `significant_drop_in_scrutinee` lint in expression context

0 files changed, 0 insertions, 0 deletions