Autocompletion of a Class that inherits from an Inner Class suggests the inherited class siblings

### Tested versions

Tested with:
- master branch (4.5)
- 4.4 branch (4.4.1)

### System information

Windows 10

### Issue description

For some reason it seems that Siblings classes of the parent class are suggested for autocompletion.
Like that:
```
# parent_container.gd
class_name ParentContainer
extends RefCounted

class Parent1:
var property1 = 0

class SiblingClass1:
var property2 = 0
```
```
# main.gd
@tool
extends EditorScript

func _run() -> void:
# when typing `ChildClass.` it adds all Siblings inner classes including itself for suggestion.
ChildClass.SiblingClass1 # this gives a parse error as intended although it was suggested
# but it is more confusing with instances.
var child_object: ChildClass = ChildClass.new()
child_object.SiblingClass1 # the error only appear during runtime interruption although it was suggested by the autocomplete feature.
```

### Steps to reproduce

Here siblings' inner classes of the parent class are suggested what happens:

Even the parent itself:

Also, this is something, but I believe it is better to be in a separate issue or feature proposal:

As autocompletion of inner classes is not supported on inheritance `extends`!

### Minimal reproduction project (MRP)

Here where I tested this behavior with multiple elements:

[InnerClassInheritance.zip](https://github.com/user-attachments/files/22198017/InnerClassInheritance.zip)

It seems that this is working as expected with parent's siblings that are attributes, methods, and signals. But not the case with siblings' inner classes.