Rollup merge of #103399 - smoelius:unknown-lint-maybe-incorrect, r=fee1-dead

Change `unknown_lint` applicability to `MaybeIncorrect`

This small PR changes the applicability of `unknown_lint` to `MaybeIncorrect`, because the suggested lint might not be the correct one.

Here is one example where the current applicability causes a problem. Clippy has a set of internal lints guarded by a feature called `internal`. If the feature is not enabled, then the internal lints are "unknown." In that case, running `cargo clippy --fix ...` on `clippy_utils` causes lines such as the followig
26c96e3416/src/tools/clippy/clippy_utils/src/paths.rs (L51-L52)
to be changed to
```rust
 #[expect(clippy::invalid_regex)] // internal lints do not know about all external crates
 pub const FUTURES_IO_ASYNCREADEXT: [&str; 3] = ["futures_util", "io", "AsyncReadExt"];
```
which is not correct.

compiler/rustc_lint/src/levels.rs

@@ -960,7 +960,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                                         sp,
                                         "did you mean",
                                         suggestion,
-                                        Applicability::MachineApplicable,
+                                        Applicability::MaybeIncorrect,
                                     );
                                 }
                                 lint