Update Rust crate hashbrown to 0.16.0 (#20399)

Coming soon: The Renovate bot (GitHub App) will be renamed to Mend. PRs
from Renovate will soon appear from 'Mend'. Learn more
[here](https://redirect.github.com/renovatebot/renovate/discussions/37842).

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [hashbrown](https://redirect.github.com/rust-lang/hashbrown) |
workspace.dependencies | minor | `0.15.0` -> `0.16.0` |

---

> [!WARNING]
> Some dependencies could not be looked up. Check the Dependency
Dashboard for more information.

---

### Release Notes

<details>
<summary>rust-lang/hashbrown (hashbrown)</summary>

###
[`v0.16.0`](https://redirect.github.com/rust-lang/hashbrown/blob/HEAD/CHANGELOG.md#0160---2025-08-28)

[Compare
Source](https://redirect.github.com/rust-lang/hashbrown/compare/v0.15.5...v0.16.0)

##### Changed

- Bump foldhash, the default hasher, to 0.2.0.
- Replaced `DefaultHashBuilder` with a newtype wrapper around `foldhash`
instead
  of re-exporting it directly.

</details>

---

### Configuration

📅 **Schedule**: Branch creation - "before 4am on Monday" (UTC),
Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you
are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

This PR was generated by [Mend Renovate](https://mend.io/renovate/).
View the [repository job
log](https://developer.mend.io/github/astral-sh/ruff).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0MS45Ny4xMCIsInVwZGF0ZWRJblZlciI6IjQxLjk3LjEwIiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6WyJpbnRlcm5hbCJdfQ==-->

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Micha Reiser <micha@reiser.io>
Co-authored-by: David Peter <mail@david-peter.de>
Co-authored-by: Ibraheem Ahmed <ibraheem@ibraheem.ca>

crates/ty_python_semantic/src/types/property_tests/type_generation.rs

@@ -7,9 +7,9 @@ use crate::types::{
     Parameters, Signature, SpecialFormType, SubclassOfType, Type, UnionType,
 };
 use crate::{Db, module_resolver::KnownModule};
-use hashbrown::HashSet;
 use quickcheck::{Arbitrary, Gen};
 use ruff_python_ast::name::Name;
+use rustc_hash::FxHashSet;
 
 /// A test representation of a type that can be transformed unambiguously into a real Type,
 /// given a db.
@@ -377,7 +377,7 @@ fn arbitrary_type(g: &mut Gen, size: u32, fully_static: bool) -> Ty {
 
 fn arbitrary_parameter_list(g: &mut Gen, size: u32, fully_static: bool) -> Vec<Param> {
     let mut params: Vec<Param> = vec![];
-    let mut used_names = HashSet::new();
+    let mut used_names = FxHashSet::default();
 
     // First, choose the number of parameters to generate.
     for _ in 0..*g.choose(&[0, 1, 2, 3, 4, 5]).unwrap() {