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

compiler/testData/diagnostics/tests/inference/genericAssignmentOperator.kt

@@ -1,9 +1,10 @@
+// FIR_IDENTICAL
 class R<T>
 
 fun <T> f(): R<T> = R<T>()
 
-operator fun Int.plusAssign(<!UNUSED_PARAMETER!>y<!>: R<Int>) {}
+operator fun Int.plusAssign(y: R<Int>) {}
 
 fun box() {
     1 += f()
-}
+}