Slow tests execution

[keradus]

after merge of #5180, the tests execution got slower

Time: 7.79 minutes, Memory: 314.50 MB

FAST_LINT_TEST_CASES=1 vendor/bin/phpunit
Time: 1.55 minutes, Memory: 280.00 MB

I see the value of having strict linter for testing purposes, but maybe we should at least aim to document the way how to run tests without that execution overhead

[github-actions]

Since this issue has not had any activity within the last 90 days, I have marked it as stale.

I will close it if no further activity occurs within the next 30 days.

[keradus]

after introduction of parallel tests executor, I consider this issue done.