groups backup has a failing case where delta
queries are not supported, but we aren't distinguishing
that case from the invalid delta case as expected. This
results in backup failures, instead of success with no data.
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#### Does this PR need a docs update or release note?
- [x] ✅ Yes, it's included
#### Type of change
- [x] 🐛 Bugfix
#### Issue(s)
* #3988
#### Test Plan
- [x] 💪 Manual
- [x] ⚡ Unit test
- [x] 💚 E2E