Remove unneeded VirtualPage "__atk_tab" code (#2197) #30540

Job	Run time
Docs	32s
Smoke (latest, Phpunit)	24s
Behat (8.1, Chrome)	5m 28s
Smoke (latest, CodingStyle)	47s
Behat (8.1, Chrome Lowest)	5m 22s
Smoke (latest, StaticAnalysis)	38s
Unit (7.4, Phpunit)	2m 11s
Behat (8.2, Chrome)	5m 20s
Unit (7.4, Phpunit Lowest)	2m 3s
Behat (8.2, Chrome Lowest)	5m 22s
Unit (8.0, Phpunit)	1m 53s
Behat (8.3, Chrome)	13m 32s
Unit (8.0, Phpunit Lowest)	1m 58s
Behat (8.3, Chrome Lowest)	5m 16s
Unit (8.1, Phpunit)	1m 59s
Behat (latest, Firefox)	5m 44s
Unit (8.1, Phpunit Lowest)	2m 5s
Behat (latest, Chrome Slow)	9m 39s
Unit (8.2, Phpunit)	1m 59s
Behat (latest, Firefox Slow)	7m 45s
Unit (8.2, Phpunit Lowest)	2m 13s
Unit (8.3, Phpunit)	3m 56s
Unit (8.3, Phpunit Lowest)	2m 0s
Unit (latest, Phpunit Burn)	5m 17s
	1h 33m 23s

Provide feedback