Revert `semtype changes` #8929

Job	Run time
Build Ballerina Lang	8m 13s
Build Ballerina Distribution	1h 6m 25s
Build Stdlib Level (1)	1m 22s
Build Stdlib Level (2)	1m 14s
Build Stdlib Level (3)	1m 18s
Build Stdlib Level (4)	1m 37s
Build Stdlib Level (5)	1m 24s
Build Stdlib Level (6)	3m 2s
Build Stdlib Level (7)	1m 58s
Build Stdlib Level (8)	26m 20s
Build Stdlib Level (9)	3m 27s
	1h 56m 20s

Provide feedback