Add step for Behat faildump storing as GHA artifact. #618

Job	Run time
CI test (make validate)	1m 4s
Code coverage (codecov)	1m 0s
SelfUpdate tests (PHAR) (8.3)	32s
SelfUpdate tests (PHAR) (8.2)	31s
SelfUpdate tests (PHAR) (8.1)	17s
SelfUpdate tests (PHAR) (8.0)	38s
SelfUpdate tests (PHAR) (7.4)	18s
Integration tests (8.3, main)	6m 18s
Build moodle-plugin-ci.phar	36s
Integration tests (8.2, MOODLE_403_STABLE)	6m 11s
Integration tests (8.2, MOODLE_402_STABLE)	5m 46s
Integration tests (8.1, MOODLE_401_STABLE)	7m 12s
Integration tests (8.0, MOODLE_400_STABLE)	6m 49s
Integration tests (8.0, MOODLE_311_STABLE)	7m 23s
Integration tests (7.4, MOODLE_39_STABLE)	5m 35s
Integration tests (PHAR) (8.3, main)	5m 35s
Integration tests (PHAR) (8.2, MOODLE_403_STABLE)	6m 4s
Integration tests (PHAR) (8.1, MOODLE_402_STABLE)	5m 33s
Integration tests (PHAR) (8.0, MOODLE_401_STABLE)	6m 47s
Integration tests (PHAR) (7.4, MOODLE_400_STABLE)	5m 46s
	1h 19m 55s

Provide feedback