chore: update findIndex tests to run mode (#5921)
chore: update findIndex tests to run mode (#5921)


martinsik/rxjs,martinsik/rxjs,ReactiveX/RxJS,martinsik/rxjs,ReactiveX/RxJS,benlesh/RxJS,ReactiveX/rxjs,ReactiveX/RxJS,benlesh/RxJS,ReactiveX/rxjs,benlesh/RxJS,ReactiveX/RxJS,ReactiveX/rxjs,ReactiveX/rxjs,benlesh/RxJS,martinsik/rxjs