⬆️ micro: Update winnow to v0.6.21 (#1194)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [winnow](https://redirect.github.com/winnow-rs/winnow) | dependencies
| patch | `0.6.20` -> `0.6.21` |

---

### Release Notes

<details>
<summary>winnow-rs/winnow (winnow)</summary>

###
[`v0.6.21`](https://redirect.github.com/winnow-rs/winnow/blob/HEAD/CHANGELOG.md#0621---2024-12-31)

[Compare
Source](https://redirect.github.com/winnow-rs/winnow/compare/v0.6.20...v0.6.21)

##### Performance

-   More inlining

##### Documentation

-   Clarify roles of `peek` and `Parser::parse_peek`
-   Provide more context for people coming from `nom`

</details>

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined),
Automerge - At any time (no schedule defined).

🚦 **Automerge**: Enabled.

♻ **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/dbus2/zbus).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOS44NS4wIiwidXBkYXRlZEluVmVyIjoiMzkuODUuMCIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOltdfQ==-->

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>