Update php Docker tag to v8.4.1 (#410)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| php | final | minor | `8.3.14-fpm-bullseye` -> `8.4.1-fpm-bullseye` |

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### Configuration

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

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Reviewed-on: #410
Co-authored-by: renovate-bot <bot@walbeck.it>
Co-committed-by: renovate-bot <bot@walbeck.it>

helix/Dockerfile

@@ -1,4 +1,4 @@
-FROM php:8.3.14-fpm-bullseye@sha256:5aa0d23f126c920df0ed465ae20a49aef53b42ac04c566cdab0d719121054240
+FROM php:8.4.1-fpm-bullseye@sha256:43462aa9b0744dbfbb6c2687b913656085d7e3ac7c7739669bd3593791971e14
 
 RUN set -ex; \
     \