[Bug]: Simple case with wrong package name of used external class

### Describe the bug

When asking to parse 2 classes a.A & b.B and a.A is using an external class c.C through b.B (see simple code below), the parser reports that a.A is using b.C instead of c.C (C belongs to package c and not b).

### Source code you are trying to analyze/transform

```Java
// First file A.java
package a;

import b.B;

public class A {

public static void callC(B b) {
b.getC().xxx();
}

}

// Second file B.java
package b;

import c.C; // external source not provided

public interface B {

C getC();

}
```

### Source code for your Spoon processing

```Java
Launcher launcher = new Launcher();
launcher.addInputResource(inputSource);
CtModel model = launcher.buildModel();

for (CtElement ctClass : model.getElements(e -> e instanceof CtClass || e instanceof CtInterface)) {
CtType ctType = (CtType) ctClass;
System.out.println(ctType.getQualifiedName() + " is using:");
for (CtTypeReference type : ctType.getUsedTypes(true)) {
System.out.println(" - " + type.getQualifiedName());
}
}
```

### Actual output

```Java
a.A is using:
- b.C
- b.B
b.B is using:
- c.C
```

### Expected output

```Java
a.A is using:
- c.C
- b.B
b.B is using:
- c.C
```

### Spoon Version

10.3.0

### JVM Version

11

### What operating system are you using?

macOS 11.7.4 (BigSur) - IntelliJ IDEA 2023.1

Start with the Launcher.buildModel() entry point and the CtType.getUsedTypes(true) and CtTypeReference.getQualifiedName() calls shown in the report. Reproduce the case using A.java and B.java, with external C unavailable, then trace type resolution for A's b.getC() call. Done means A reports c.C rather than b.C while B continues to report c.C.

Written by the indexing model from the issue text.