build(deps): update axllent/mailpit to v1.20.3

This MR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [axllent/mailpit](https://github.com/axllent/mailpit) | patch | `v1.20.2` -> `v1.20.3` |

MR created with the help of [el-capitano/tools/renovate-bot](https://gitlab.com/el-capitano/tools/renovate-bot).

**Proposed changes to behavior should be submitted there as MRs.**

---

### Release Notes

<details>
<summary>axllent/mailpit (axllent/mailpit)</summary>

### [`v1.20.3`](https://github.com/axllent/mailpit/blob/HEAD/CHANGELOG.md#v1203)

[Compare Source](axllent/mailpit@v1.20.2...v1.20.3)

##### Chore

-   Update caniemail database
-   Update node dependencies
-   Update Go dependencies
-   Do not recenter selected messages in sidebar on every new message

##### Fix

-   Disable automatic HTML/Text character detection when charset is provided ([#&#8203;348](axllent/mailpit#348))

</details>

---

### Configuration

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

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

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

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

---

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

---

This MR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy40NDAuNyIsInVwZGF0ZWRJblZlciI6IjM3LjQ0MC43IiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6WyJSZW5vdmF0ZSBCb3QiXX0=-->

chezmoi/dot_config/aquaproj-aqua/aqua.yaml

@@ -277,7 +277,7 @@ packages:
 - name: yassinebridi/serpl@0.3.3
   description: A simple terminal UI for search and replace, ala VS Code
   link: https://github.com/yassinebridi/serpl
-- name: axllent/mailpit@v1.20.2
+- name: axllent/mailpit@v1.20.3
   description: An email and SMTP testing tool with API for developers
   link: https://github.com/axllent/mailpit
 - name: mrjackwills/oxker@v0.7.0