Adjust filter plugin validation requirements to comply with Moodle 4.5 #714

Job	Run time
Code coverage (codecov)	1m 1s
CI test (make validate)	56s
Build moodle-plugin-ci.phar	25s
Integration tests (8.3, main, true)	6m 28s
Integration tests (8.3, MOODLE_405_STABLE, true)	6m 26s
Integration tests (8.3, MOODLE_404_STABLE, true)	6m 20s
Integration tests (8.2, MOODLE_403_STABLE, true)	6m 8s
Integration tests (8.2, MOODLE_402_STABLE, true)	6m 8s
Integration tests (8.1, MOODLE_401_STABLE, true)	6m 42s
Integration tests (8.0, MOODLE_400_STABLE)	5m 46s
Integration tests (8.0, MOODLE_311_STABLE)	5m 1s
Integration tests (7.4, MOODLE_39_STABLE)	4m 57s
SelfUpdate tests (PHAR) (8.3)	32s
Integration tests (PHAR) (8.3, main, true)	6m 17s
SelfUpdate tests (PHAR) (8.2)	31s
Integration tests (PHAR) (8.3, MOODLE_405_STABLE, true)	6m 4s
SelfUpdate tests (PHAR) (8.1)	20s
Integration tests (PHAR) (8.3, MOODLE_404_STABLE, true)	6m 18s
SelfUpdate tests (PHAR) (8.0)	27s
Integration tests (PHAR) (8.2, MOODLE_403_STABLE, true)	5m 47s
SelfUpdate tests (PHAR) (7.4)	9s
Integration tests (PHAR) (8.1, MOODLE_402_STABLE, true)	5m 31s
Integration tests (PHAR) (8.0, MOODLE_401_STABLE, true)	6m 1s
Integration tests (PHAR) (7.4, MOODLE_400_STABLE)	5m 15s
	1h 39m 30s

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