Add MOODLE_405_STABLE to GHA/Travis tests #706

Job	Run time
CI test (make validate)	1m 11s
Code coverage (codecov)	55s
Build moodle-plugin-ci.phar	33s
Integration tests (8.3, main, true)	6m 34s
Integration tests (8.3, MOODLE_405_STABLE, true)	7m 4s
Integration tests (8.3, MOODLE_404_STABLE, true)	6m 52s
Integration tests (8.2, MOODLE_403_STABLE, true)	6m 41s
Integration tests (8.2, MOODLE_402_STABLE, true)	6m 17s
Integration tests (8.1, MOODLE_401_STABLE, true)	7m 8s
Integration tests (8.0, MOODLE_400_STABLE)	6m 4s
Integration tests (8.0, MOODLE_311_STABLE)	5m 9s
Integration tests (7.4, MOODLE_39_STABLE)	4m 51s
SelfUpdate tests (PHAR) (8.3)	36s
SelfUpdate tests (PHAR) (8.2)	39s
Integration tests (PHAR) (8.3, main, true)	6m 38s
SelfUpdate tests (PHAR) (8.1)	32s
Integration tests (PHAR) (8.3, MOODLE_405_STABLE, true)	6m 25s
SelfUpdate tests (PHAR) (8.0)	24s
Integration tests (PHAR) (8.3, MOODLE_404_STABLE, true)	5m 56s
SelfUpdate tests (PHAR) (7.4)	7s
Integration tests (PHAR) (8.2, MOODLE_403_STABLE, true)	6m 25s
Integration tests (PHAR) (8.1, MOODLE_402_STABLE, true)	5m 37s
Integration tests (PHAR) (8.0, MOODLE_401_STABLE, true)	6m 16s
Integration tests (PHAR) (7.4, MOODLE_400_STABLE)	4m 52s
	1h 43m 46s

Provide feedback