Update stalwartlabs/stalwart Docker tag to v0.15.0 (#2672)

This PR contains the following updates:

| Package | Update | Change | Pending |
|---|---|---|---|
| [stalwartlabs/stalwart](https://github.com/stalwartlabs/stalwart) | minor | `v0.14.1` -> `v0.15.0` | `v0.15.1` |

---

### Release Notes

<details>
<summary>stalwartlabs/stalwart (stalwartlabs/stalwart)</summary>

### [`v0.15.0`](https://github.com/stalwartlabs/stalwart/releases/tag/v0.15.0)

[Compare Source](https://github.com/stalwartlabs/stalwart/compare/v0.14.1...v0.15.0)

#### \[0.15.0] - 2025-12-16

This version includes **multiple breaking changes**. Please read the [upgrading documentation](https://github.com/stalwartlabs/stalwart/blob/main/UPGRADING/v0_15.md) for more information on how to upgrade from previous versions.

#### Added

- Linear spam classifier using FTRL-Proximal and feature/cuckoo hashing.
- Meilisearch store backend implementation ([#&#8203;1482](https://github.com/stalwartlabs/stalwart/issues/1482)).
- PostgreSQL and mySQL native full-text search support.
- Multiple performance improvements and database access optimizations.
- Encryption-at-rest: Spam training privacy setting.
- Enterprise: Undelete e-mail feature now includes From/Subject/Received information.
- IMAP: Implemented new keywords and mailbox attributes described in [draft-ietf-mailmaint-messageflag-mailboxattribute-13](https://datatracker.ietf.org/doc/html/draft-ietf-mailmaint-messageflag-mailboxattribute-13)

#### Changed

- IMAP: Always return special use flags in responses.

#### Fixed

- JMAP: `FileNode/set` fails to delete files ([#&#8203;2485](https://github.com/stalwartlabs/stalwart/issues/2485)).
- JMAP: Return error when using `blobId` in JSContact and JSCalendar ([#&#8203;2431](https://github.com/stalwartlabs/stalwart/issues/2431)).
- Directory: Deletion of list or domain issues ([#&#8203;2415](https://github.com/stalwartlabs/stalwart/issues/2415)).
- MTA: Headers and body stripped from mail delivery subsystem failure notifications ([#&#8203;2344](https://github.com/stalwartlabs/stalwart/issues/2344)).
- MTA: Hooks only run if sieve script, milter or rewrite is configured ([#&#8203;2317](https://github.com/stalwartlabs/stalwart/issues/2317)).
- Autodiscover: Endpoint should be case insensitive ([#&#8203;2440](https://github.com/stalwartlabs/stalwart/issues/2440)).
- Housekeeper: Panic during DST transition ([#&#8203;2366](https://github.com/stalwartlabs/stalwart/issues/2366)).
- Import/Export: Fix import/export utility ([#&#8203;1882](https://github.com/stalwartlabs/stalwart/issues/1882)).
- Enterprise: Remove tenant admin permissions when license is invalid.

<hr />

##### Check binary attestation at [here](https://github.com/stalwartlabs/stalwart/attestations/15221862)

</details>

---

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---

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---

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Reviewed-on: https://gitea.alexlebens.dev/alexlebens/infrastructure/pulls/2672
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clusters/cl01tl/helm/stalwart/values.yaml

@@ -9,7 +9,7 @@ stalwart:
         main:
           image:
             repository: stalwartlabs/stalwart
-            tag: v0.14.1
+            tag: v0.15.0
             pullPolicy: IfNotPresent
           resources:
             requests: