Reduce Spinach parallelization to 4 nodes and increase RSpec's to 26 nodes
What does this MR do?
Since we have less and less Spinach tests, it's good to regularly re-balance the number of test nodes we allocate for RSpec vs Spinach.
New allocation is:
- RSpec: 26 nodes
- Spinach: 4 nodes
Are there points in the code the reviewer needs to double check?
Spinach and RSpec jobs should roughly finish with the same duration.