Wagtail site history doesn't work

[nutjob4life]

🐛 Describe the Bug

Wagtail has a nice feature called the Site History where you can see who did what and at what time. It's great for finding out if a page was accidentally deleted or if someone made an edit some place you didn't expect.

The problem is: the nightly ingest fills up the Site History with 10k entries every night, and so the feature doesn't work.

📜 How To Reproduce

1. Go to the portal admin
2. On the admin menu, choose "Reports"
3. Click "Site history"

Eventually you get "502 gateway error"

🔎 Expected Behavior

You should see the site history