Revert "Remove unnecessary `map`" #276

Job	Run time
test-windows (head)	2m 24s
test-memory (head)	24s
check-misc (head)	10s
test-ruby (head, master)	4m 56s
steep-check (head)	12s
test-ruby (3.0, master)	5m 18s
test-ruby (2.7, master)	6m 6s
ruby-versions / Generate Ruby versions	3s
test (2.5)	21s
test (2.6)	26s
test (2.7)	22s
test (3.0)	10s
test (3.1)	14s
test (3.2)	9s
test (3.3)	10s
test (head)	10s
	21m 35s

Provide feedback