[FIR] Add opt-in to replaceIsTrailingLambda

#KT-66553

compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/LightTreeRawFirExpressionBuilder.kt

@@ -1515,6 +1515,8 @@ class LightTreeRawFirExpressionBuilder(
                 LABELED_EXPRESSION,
                 ANNOTATED_EXPRESSION,
                 -> container += getAsFirExpression<FirAnonymousFunctionExpression>(node).apply {
+                    // TODO(KT-66553) remove and set in builder
+                    @OptIn(RawFirApi::class)
                     replaceIsTrailingLambda(newIsTrailingLambda = true)
                 }
             }