[Bug]: If there is no parent class source code, invocation.getExecutable() will incorrectly locate other method in this class

### Describe the bug

When I use Spoon analysis, if there is no parent class source code, invocation.getExecutable() will incorrectly locate other method in this class.

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

```Java
public abstract class A extends Father {
@Override
public void add(double x) {
add(x, 1);
}

abstract void add(double x, int w, int base);
}
```

### Source code for your Spoon processing

_No response_

### Actual output

_No response_

### Expected output

_No response_

### Spoon Version

10.3.0

### JVM Version

15

### What operating system are you using?

win11