Further decrease of amount of parallelism

[potiuk]

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Issue link: WILL BE INSERTED BY boring-cyborg

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[dimberman]

@potiuk why change this?

[potiuk]

@potiuk why change this?

Seems that it still fails from time to time in the latest builds (it consistently worked yesterday but there were a few failed builds today)

[codecov-io]

Codecov Report

Merging #7991 into master will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #7991      +/-   ##
==========================================
- Coverage   87.17%   87.16%   -0.01%     
==========================================
  Files         932      932              
  Lines       45187    45187              
==========================================
- Hits        39391    39389       -2     
- Misses       5796     5798       +2     

Impacted Files	Coverage Δ
airflow/utils/dag_processing.py	87.94% <0.00%> (-0.38%)	⬇️

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[potiuk]

Seems it helps ! @dimberman ?