chore(deps): update rust crate cargo_metadata to 0.21.0 (#15795)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [cargo_metadata](https://redirect.github.com/oli-obk/cargo_metadata) |
workspace.dependencies | minor | `0.20.0` -> `0.21.0` |

---

### Release Notes

<details>
<summary>oli-obk/cargo_metadata (cargo_metadata)</summary>

###
[`v0.21.0`](https://redirect.github.com/oli-obk/cargo_metadata/compare/0.20.0...0.21.0)

[Compare
Source](https://redirect.github.com/oli-obk/cargo_metadata/compare/0.20.0...0.21.0)

</details>

---

### Configuration

📅 **Schedule**: Branch creation - "before 5am on the first day of the
month" (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/rust-lang/cargo).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0MS40Ni4zIiwidXBkYXRlZEluVmVyIjoiNDEuNDYuMyIsInRhcmdldEJyYW5jaCI6Im1hc3RlciIsImxhYmVscyI6W119-->

Author: epage

Cargo.lock

@@ -35,7 +35,7 @@ cargo-test-macro = { version = "0.4.4", path = "crates/cargo-test-macro" }
 cargo-test-support = { version = "0.8.0", path = "crates/cargo-test-support" }
 cargo-util = { version = "0.2.22", path = "crates/cargo-util" }
 cargo-util-schemas = { version = "0.10.0", path = "crates/cargo-util-schemas" }
-cargo_metadata = "0.20.0"
+cargo_metadata = "0.21.0"
 clap = "4.5.40"
 clap_complete = { version = "4.5.54", features = ["unstable-dynamic"] }
 color-print = "0.3.7"