chore: Update systemd journal configuration

[nadeemshahzad]

This will set maximum disk space usage, free space, retention, and file age for the systemd journal. The settings have been adjusted as follows:

• SystemMaxUse: 500M
• SystemKeepFree: 1G
• MaxRetentionSec: 1month
• MaxFileSec: 1week

These changes ensure better management of disk space and retention of journal logs.

Configuration Pull Request

Make sure that the following steps are done before merging:

• Have a Site Reliability Engineer review the PR if you don't own all of the services impacted.
• If you are adding any new default values that need to be overridden when this change goes live, update internal repos and add an entry to the top of the CHANGELOG.
• Performed the appropriate testing.
• Think about how this change will affect Open edX operators and update the wiki page for the next Open edX release if needed