quality_control: correct the per-class accuracy formula #13002

Job	Run time
search_cache / search_cache	5s
build	8m 16s
rest_api_testing	17m 35s
e2e_testing (actions_tasks)	13m 22s
unit_testing	12m 33s
e2e_testing (actions_tasks2)	21m 5s
e2e_testing (actions_tasks3)	15m 40s
e2e_testing (actions_objects)	9m 59s
e2e_testing (actions_objects2)	11m 10s
e2e_testing (actions_users)	8m 35s
e2e_testing (actions_projects_models)	9m 40s
e2e_testing (canvas3d_functionality)	8m 49s
e2e_testing (canvas3d_functionality_2)	8m 10s
e2e_testing (issues_prs)	11m 16s
e2e_testing (issues_prs2)	12m 50s
e2e_testing (features)	12m 42s
generate_github_pages	3m 3s
codecov	21s
publish_dev_images	0s
	3h 5m 11s

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