ENH Remove code that had been retained for backwards compatibility #3600

Job	Run time
CI / Generate matrix	15s
CI / Context	1s
CI / 8.3 prf-low mariadb phpunit framework-core	6m 14s
CI / Check governance	0s
CI / 8.3 mysql80 phpunit framework-core	7m 52s
CI / 8.4 mysql84 phpunit framework-core	7m 36s
CI / 8.3 prf-low mariadb phpunit framework-orm	12m 33s
CI / 8.3 mysql80 phpunit framework-orm	13m 58s
CI / 8.4 mysql84 phpunit framework-orm	13m 26s
CI / 8.3 mysql80 phplinting	2m 36s
CI / 8.3 mysql80 phpunit framework-cache-only inmemorycache	1m 27s
CI / Dispatch tag patch release	0s
	1h 5m 58s

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