perf: Use Hashbrown for array_distinct (#20538)

## Which issue does this PR close?

N/A

## Rationale for this change

#20364 recently optimized `array_distinct` to use batched row
conversion. As part of that PR, `std::HashSet` was used. This PR just
replaces `std::HashSet` with `hashbrown::HashSet`, which measurably
improves performance.

## What changes are included in this PR?

## Are these changes tested?

Yes.

## Are there any user-facing changes?

No.

Author: neilconway

datafusion/functions-nested/src/set_ops.rs

@@ -34,8 +34,8 @@ use datafusion_expr::{
     ColumnarValue, Documentation, ScalarUDFImpl, Signature, Volatility,
 };
 use datafusion_macros::user_doc;
+use hashbrown::HashSet;
 use std::any::Any;
-use std::collections::HashSet;
 use std::fmt::{Display, Formatter};
 use std::sync::Arc;