Update Rust crate async-compression to v0.4.21 (#27122)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[async-compression](https://redirect.github.com/Nullus157/async-compression)
| workspace.dependencies | patch | `0.4.20` -> `0.4.21` |

---

### Release Notes

<details>
<summary>Nullus157/async-compression (async-compression)</summary>

###
[`v0.4.21`](https://redirect.github.com/Nullus157/async-compression/blob/HEAD/CHANGELOG.md#0421---2025-03-15)

[Compare
Source](https://redirect.github.com/Nullus157/async-compression/compare/v0.4.20...v0.4.21)

##### Fixed

- When flate encoding, do not mark internal state as flushed if it ran
out of buffer space.
- Add debug assertion in `produce` method to check buffer capacity in
implementations for `BufWriter`.

</details>

---

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---

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---

Release Notes:

- N/A

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Cargo.lock

@@ -795,9 +795,9 @@ dependencies = [
 
 [[package]]
 name = "async-compression"
-version = "0.4.20"
+version = "0.4.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "310c9bcae737a48ef5cdee3174184e6d548b292739ede61a1f955ef76a738861"
+checksum = "c0cf008e5e1a9e9e22a7d3c9a4992e21a350290069e36d8fb72304ed17e8f2d2"
 dependencies = [
  "deflate64",
  "flate2",