feat: use new separate file to store journald config for new log retention policy

tasks/configure_persistent_journald_logging.yml

@@ -8,6 +8,15 @@
     mode: "0644"
     create: "true"
     state: present
+  loop:
+    - path: "log_retention.conf"
+      block: |
+      # According to SLUB policy beginning in July 2023, there are new retention periods for log entries governed by the law (SächsISichG §13). From now on, logs in journald are stored for 90 days, as reflected by this configuration.
+      # Find details on this configuration item at https://www.freedesktop.org/software/systemd/man/journald.conf.html#MaxFileSec=
+      MaxFileSec=1day
+      # Find details on this configuration item at https://www.freedesktop.org/software/systemd/man/journald.conf.html#MaxRetentionSec=
+      MaxRetentionSec=90day
+    - path: "persistence.conf"
       block: |
       # If "persistent", data will be stored preferably on disk, i.e. below the /var/log/journal hierarchy (which is created if needed), with a fallback to /run/log/journal (which is created if needed), during early boot and if the disk is not writable.
       Storage=persistent