Refactor runtime type checker concurrency model #8863

Job	Run time
Build Ballerina Lang	7m 35s
Build Ballerina Distribution	1h 5m 45s
Build Stdlib Level (1)	3m 57s
Build Stdlib Level (10)	11m 3s
Build Stdlib Level (2)	12m 49s
Build Stdlib Level (3)	8m 45s
Build Stdlib Level (4)	9m 22s
Build Stdlib Level (5)	3m 31s
Build Stdlib Level (6)	6m 8s
Build Stdlib Level (7)	4m 18s
Build Stdlib Level (8)	1h 28m 10s
Build Stdlib Level (9)	5m 19s
	3h 46m 42s

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