chore(deps): update traefik docker tag to v3.6.8 (#89)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [traefik](https://github.com/containous/traefik) | patch | `v3.6.7` -> `v3.6.8` |

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Reviewed-on: coop-cloud/traefik#89
Reviewed-by: p4u1 <p4u1@noreply.git.coopcloud.tech>
Reviewed-by: decentral1se <decentral1se@noreply.git.coopcloud.tech>
Co-authored-by: Renovate Bot <renovate@coopcloud.tech>
Co-committed-by: Renovate Bot <renovate@coopcloud.tech>

compose.yml

@@ -3,7 +3,7 @@ version: "3.8"
 
 services:
   app:
-    image: "traefik:v3.6.7"
+    image: "traefik:v3.6.8"
     # Note(decentral1se): *please do not* add any additional ports here.
     # Doing so could break new installs with port conflicts. Please use
     # the usual `compose.$app.yml` approach for any additional ports