[FIR] KT-54260: Fix the compiler crash

AllOpen plugin makes the properties all-open, but the annotation class
is left closed, because allopen for k2 literally checks
`classKind == CLASS`.

Since the properties are open, a
`NON_FINAL_MEMBER_IN_FINAL_CLASS` diagnostic is reported for them. It's
positioning strategy seeks for the explicit `open` modifier which is
not present.

The added test should not crash the compiler.

^KT-54260 Fixed

plugins/allopen/testData/diagnostics/kt54260.kt

@@ -0,0 +1,10 @@
+// FIR_IDENTICAL
+// WITH_STDLIB
+
+annotation class AllOpen
+
+@AllOpen
+annotation class ConsoleCommands(
+    val <!NON_FINAL_MEMBER_IN_FINAL_CLASS!>value<!>: String = "",
+    val <!NON_FINAL_MEMBER_IN_FINAL_CLASS!>scope<!>: String
+)