SweepData returns only the first frequency data

### 🔍 Before submitting the issue

- [x] I have searched among the existing issues
- [x] I am using a Python virtual environment

### 🐞 Description of the bug

The sweep has two frequency data. The SweepData obj in pyedb core returns always only the first

### 📝 Steps to reproduce

### 💻 Which operating system are you using?

Windows

### 📀 Which ANSYS version are you using?

_No response_

### 🐍 Which Python version are you using?

3.9

### 📦 Installed packages

```shell
annotated-types 0.7.0
ansys-api-edb 0.3.2
ansys-edb-core 0.3.2
ansys-tools-common 0.5.0
certifi 2026.5.20
charset-normalizer 3.4.7
click 8.4.0
colorama 0.4.6
contourpy 1.3.3
cycler 0.12.1
defusedxml 0.7.1
fonttools 4.63.0
grpcio 1.80.0
idna 3.15
iniconfig 2.3.0
kiwisolver 1.5.0
matplotlib 3.11.0
numpy 2.4.6
packaging 26.2
pandas 3.0.3
pillow 12.2.0
pip 26.0.1
platformdirs 4.9.6
pluggy 1.6.0
protobuf 6.33.6
psutil 7.2.2
pydantic 2.13.4
pydantic_core 2.46.4
Pygments 2.20.0
pyparsing 3.3.2
pytest 9.1.0
python-dateutil 2.9.0.post0
requests 2.34.2
rtree 1.4.1
scikit-rf 1.12.0
scipy 1.17.1
scooby 0.11.2
six 1.17.0
toml 0.10.2
typing_extensions 4.15.0
typing-inspection 0.4.2
tzdata 2026.2
urllib3 2.7.0
xmltodict 1.0.4
```

Start by reproducing the issue with the SweepData object in pyedb-core using sweep data that contains two frequencies. Trace how the object retrieves frequency data and verify that the completed behavior returns both frequencies rather than only the first.

Written by the indexing model from the issue text.