refactor: use NightshadeRuntime in store_validator tests

[pugachAG]

Part of #10678 and #10634.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.11%. Comparing base (1ab5d1b) to head (2c2537a).
Report is 9 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #10690      +/-   ##
==========================================
- Coverage   72.16%   72.11%   -0.06%     
==========================================
  Files         737      737              
  Lines      150811   150872      +61     
  Branches   150811   150872      +61     
==========================================
- Hits       108831   108796      -35     
- Misses      37044    37116      +72     
- Partials     4936     4960      +24     

Flag	Coverage Δ
backward-compatibility	0.24% <ø> (-0.01%)	⬇️
db-migration	0.24% <ø> (-0.01%)	⬇️
genesis-check	1.40% <ø> (-0.01%)	⬇️
integration-tests	37.09% <0.00%> (+0.08%)	⬆️
linux	70.93% <100.00%> (-0.05%)	⬇️
linux-nightly	71.54% <100.00%> (-0.06%)	⬇️
macos	55.16% <100.00%> (-0.03%)	⬇️
pytests	1.63% <ø> (-0.04%)	⬇️
sanity-checks	1.41% <ø> (-0.01%)	⬇️
unittests	67.94% <100.00%> (-0.07%)	⬇️
upgradability	0.29% <ø> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[wacban]

LGTM