Drop obsolete TODO during FIR building

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

@@ -89,6 +89,7 @@ inline fun isClassLocal(classNode: LighterASTNode, getParent: LighterASTNode.()
                 parent?.tokenType == KT_FILE -> return true
                 parent?.tokenType == CLASS_BODY && !(grandParent?.tokenType == OBJECT_DECLARATION && grandParent?.getParent()?.tokenType == OBJECT_LITERAL) -> return true
                 parent?.tokenType == BLOCK && grandParent?.tokenType == SCRIPT -> return true
+                // NB: enum entry nested classes are considered local by FIR design (see discussion in KT-45115)
                 parent?.tokenType == ENUM_ENTRY -> return true
             }
         }

compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt

@@ -793,11 +793,8 @@ class RawFirBuilder(
         override fun visitClassOrObject(classOrObject: KtClassOrObject, data: Unit): FirElement {
             return withChildClassName(
                 classOrObject.nameAsSafeName,
-                classOrObject.isLocal
-                        // TODO: currently enum entry initializer is represented in FIR as an FirAnonymousObject. Because of this, all
-                        //  nested declarations are now marked local. This causes the FirNestedClassChecker to ignore some invalid programs.
-                        // See KT-45115
-                        || classOrObject.getStrictParentOfType<KtEnumEntry>() != null
+                // NB: enum entry nested classes are considered local by FIR design (see discussion in KT-45115)
+                isLocal = classOrObject.isLocal || classOrObject.getStrictParentOfType<KtEnumEntry>() != null
             ) {
                 val classKind = when (classOrObject) {
                     is KtObjectDeclaration -> ClassKind.OBJECT