Auto merge of #8692 - kyoto7250:fixing_unnecessary_to_owned, r=giraffate

fix unnecessary_to_owned about msrv

This PR fixes ``[`unnecessary_owned`]``.

## What

```rust
# sample code
fn _msrv_1_35() {
    #![clippy::msrv = "1.35"]
    let _ = &["x"][..].to_vec().into_iter();
}

fn _msrv_1_36() {
    #![clippy::msrv = "1.36"]
    let _ = &["x"][..].to_vec().into_iter();
}
```

If we will check this code using clippy, ``[`unnecessary_owned`]`` will modify the code as follows.

```rust
error: unnecessary use of `to_vec`
  --> $DIR/unnecessary_to_owned.rs:219:14
   |
LL |     let _ = &["x"][..].to_vec().into_iter();
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `["x"][..].iter().copied()`

error: unnecessary use of `to_vec`
  --> $DIR/unnecessary_to_owned.rs:224:14
   |
LL |     let _ = &["x"][..].to_vec().into_iter();
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `["x"][..].iter().copied()`
```

This is incorrect. Because `Iterator::copied` was estabilished in 1.36.

## Why

This bug was caused by not separating "copied" and "clone" by reference to msrv.

https://github.com/rust-lang/rust-clippy/blob/89ee6aa6e32df974ef9dbb3c825afbdce441e856/clippy_lints/src/methods/unnecessary_to_owned.rs#L195

So, I added a conditional branch and described the corresponding test.

Thank you in advance.

changelog: fix wrong suggestions about msrv in [`unnecessary_to_owned`]

r! `@giraffate`

0 files changed, 0 insertions, 0 deletions