[Test] Disable UNUSED_* diagnostics in tests which are not belong to contolFlowAnalysis suite

compiler/testData/diagnostics/tests/labels/kt3988.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 //KT-3988 This@label for outer function not resolved
 
 class Comment() {
@@ -15,7 +16,7 @@ fun new2(body: Comment2.() -> Unit) = body
 fun main() {
     new {
         new2 {
-            <!UNUSED_EXPRESSION!>this@new<!> //UNRESOLVED REFERENCE
+            this@new //UNRESOLVED REFERENCE
         }
     }
-}
+}