chore(deps): update nextcloud docker tag to v29 (#54)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| nextcloud | major | `28.0.5` -> `29.0.0` |

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### Configuration

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Reviewed-on: #54
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Co-committed-by: Renovate Bot <renovate@mgrote.net>

docker-compose/nextcloud/docker-compose.yml.j2

@@ -66,7 +66,7 @@ services:
 
 ######## Nextcloud ########
   nextcloud-app:
-    image: "nextcloud:28.0.5"
+    image: "nextcloud:29.0.0"
     container_name: nextcloud-app
     restart: unless-stopped
     depends_on: