[FIR] Ignore CFA-only edges in DFA even if they are dead

^KT-53920 Fixed

compiler/fir/analysis-tests/testData/resolve/cfg/anonymousObjectInUnreachableCode.fir.txt

@@ -0,0 +1,11 @@
+FILE: anonymousObjectInUnreachableCode.kt
+    public final fun test(): R|kotlin/Unit| {
+        ^test Unit
+        object : R|kotlin/Any| {
+            private constructor(): R|<anonymous>| {
+                super<R|kotlin/Any|>()
+            }
+
+        }
+
+    }