[FIR] Don't traverse expect hierarchy to check DefaultArgumentsInExpectActualizedByFakeOverride

^KT-63860 Fixed
Review: https://jetbrains.team/p/kt/reviews/13334/timeline

The previous code was nonsense (I wrote it). It doesn't make sense to
subtract actualOverriddenDeclarations from expectOverriddenDeclarations.
Default parameters are mentioned on the expect side. So default params
in expect/actual supertypes won't be subtracted from
expectOverriddenDeclarations (but should be)

compiler/testData/diagnostics/tests/multiplatform/kt63860.kt

@@ -0,0 +1,26 @@
+// FIR_IDENTICAL
+// MODULE: m1-common
+// FILE: common.kt
+
+expect interface SdkBufferedSink {
+    public fun write(arg: String = "default")
+}
+
+abstract class AbstractBufferedSinkAdapter() : SdkBufferedSink {
+    override fun write(arg: String) {
+    }
+}
+
+expect class BufferedSinkAdapter() : SdkBufferedSink {
+    override fun write(arg: String)
+}
+
+// MODULE: m2-jvm()()(m1-common)
+// FILE: jvm.kt
+
+actual interface SdkBufferedSink {
+    public actual fun write(arg: String): Unit
+}
+
+actual class BufferedSinkAdapter actual constructor() : AbstractBufferedSinkAdapter(), SdkBufferedSink {
+}

compiler/testData/diagnostics/tests/multiplatform/kt63860_2.kt

@@ -0,0 +1,26 @@
+// FIR_IDENTICAL
+// MODULE: m1-common
+// FILE: common.kt
+
+expect interface SdkBufferedSink {
+    public fun write(arg: String = "default")
+}
+
+abstract class AbstractBufferedSinkAdapter() {
+    fun write(arg: String) {
+    }
+}
+
+expect class BufferedSinkAdapter() : SdkBufferedSink {
+    override fun write(arg: String)
+}
+
+// MODULE: m2-jvm()()(m1-common)
+// FILE: jvm.kt
+
+actual interface SdkBufferedSink {
+    public actual fun write(arg: String): Unit
+}
+
+actual class BufferedSinkAdapter actual constructor() : AbstractBufferedSinkAdapter(), SdkBufferedSink {
+}