[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/sealed/NeverDerivedFromNested.fir.kt

@@ -0,0 +1,9 @@
+class A {
+    sealed class Base
+}
+
+class Derived : A.Base()
+
+fun test() {
+    class DerivedLocal : A.Base()
+}