Revert "[test] Disable test to unblock CI"

This reverts commit e3a125a.

Author: eeckstein

validation-test/SILOptimizer/large_string_array.swift.gyb

@@ -4,8 +4,6 @@
 // https://github.com/apple/swift/issues/56816
 // UNSUPPORTED: OS=linux-gnu
 
-// REQUIRES: rdar162433770
-
 // The compiler should finish in less than 1 minute. To give some slack,
 // specify a timeout of 5 minutes.
 // If the compiler needs more than 5 minutes, there is probably a real problem.