Change stability testing sizes to avoid domain overlap with MPI

[mloubout]

No description provided.

[codecov]

Codecov Report

Merging #1772 (f02c8de) into master (10768c8) will decrease coverage by 0.15%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##           master    #1772      +/-   ##
==========================================
- Coverage   89.47%   89.32%   -0.16%     
==========================================
  Files         208      203       -5     
  Lines       33937    33385     -552     
  Branches     4408     4375      -33     
==========================================
- Hits        30366    29822     -544     
+ Misses       3074     3060      -14     
- Partials      497      503       +6     

Impacted Files	Coverage Δ
examples/seismic/acoustic/acoustic_example.py	31.48% <66.66%> (-19.43%)	⬇️
examples/seismic/elastic/elastic_example.py	48.57% <66.66%> (-29.21%)	⬇️
examples/seismic/tti/tti_example.py	36.11% <66.66%> (-20.65%)	⬇️
...les/seismic/viscoacoustic/viscoacoustic_example.py	46.15% <66.66%> (-23.85%)	⬇️
...mples/seismic/viscoelastic/viscoelastic_example.py	48.57% <66.66%> (-29.21%)	⬇️
examples/seismic/acoustic/operators.py	79.48% <0.00%> (-16.67%)	⬇️
... and 14 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 10768c8...f02c8de. Read the comment docs.

[FabioLuporini]

uncontroversial