Fix counting in Slack report for some jobs
# What does this PR do?

Fix counting in Slack report for some jobs.

### Context
For the additional jobs (i.e. not model testing jobs), the number of failed tests are being summed across over all machine types (single/multi - gpu). We have strange things like single gpu deepspeed CI has only 1 failure but 86 was shown on the report, see:


<img width="812" alt="image" src="https://user-images.githubusercontent.com/2521628/233582320-81c3b61d-add4-4ad5-b007-2522ad0f44b3.png">




_The documentation is not available anymore as the PR was closed or merged._