key error "pop from an empty set"

### 🔍 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 following error is given when using the `add_design_point()` command;
```
Traceback (most recent call last):
File "/Fluent_Parametric.py", line 49, in
dp1 = study2.add_design_point()
File "/.venv/lib/python3.10/site-packages/ansys/fluent/parametric/__init__.py", line 362, in add_design_point
dp_name = set(dps_after).difference(set(dps_before)).pop()
KeyError: 'pop from an empty set'
```

### 📝 Steps to reproduce

run attached script based on parametric example
[adesign_point_error.zip](https://github.com/ansys/pyfluent-parametric/files/14600671/adesign_point_error.zip)

### 💻 Which operating system are you using?

Linux

### 📀 Which ANSYS version are you using?

v242

### 🐍 Which Python version are you using?

3.10

### 📦 Installed packages

```shell
absl-py==2.1.0
ansys-api-fluent==0.3.22
ansys-api-platform-instancemanagement==1.0.0
ansys-fluent-core==0.20.dev8
ansys-fluent-parametric @ file:///.venv/pyfluent-parametric
ansys-fluent-visualization @ file:///jomiller/.venv/pyfluent-visualization
ansys-platform-instancemanagement==1.1.2
ansys-units==0.3.1
asttokens==2.4.1
astunparse==1.6.3
bcrypt==4.1.2
beartype==0.17.2
blinker==1.7.0
certifi==2024.2.2
cffi==1.16.0
charset-normalizer==3.3.2
click==8.1.7
contourpy==1.2.0
cryptography==42.0.5
cycler==0.12.1
dash==2.16.1
dash-bootstrap-components==1.5.0
dash-core-components==2.0.0
dash-html-components==2.0.0
dash-table==5.0.0
decorator==5.1.1
dm-tree==0.1.8
docker==6.1.3
et-xmlfile==1.1.0
exceptiongroup==1.2.0
executing==2.0.1
Flask==3.0.2
flatbuffers==24.3.7
fonttools==4.49.0
gast==0.5.4
google-pasta==0.2.0
grpcio==1.62.1
grpcio-health-checking==1.49.0rc1
h5py==3.10.0
idna==3.6
imageio==2.34.0
importlib_metadata==7.0.2
iniconfig==2.0.0
ipython==8.22.2
itsdangerous==2.1.2
jedi==0.19.1
Jinja2==3.1.3
joblib==1.3.2
kaleido==0.2.1
keras==3.0.5
kiwisolver==1.4.5
libclang==16.0.6
lxml==4.9.4
Markdown==3.5.2
markdown-it-py==3.0.0
MarkupSafe==2.1.5
matplotlib==3.8.3
matplotlib-inline==0.1.6
mdurl==0.1.2
ml-dtypes==0.3.2
namex==0.0.7
nest-asyncio==1.6.0
numpy==1.26.4
openpyxl==3.1.2
opt-einsum==3.3.0
packaging==24.0
pandas==1.5.3
paramiko==3.4.0
paramiko-expect==0.3.5
parso==0.8.3
pexpect==4.9.0
pillow==10.2.0
platformdirs==3.11.0
plotly==5.20.0
pluggy==1.4.0
pooch==1.8.1
prompt-toolkit==3.0.43
protobuf==3.20.3
psutil==5.9.8
ptyprocess==0.7.0
pure-eval==0.2.2
pycparser==2.21
Pygments==2.17.2
PyNaCl==1.5.0
pyparsing==3.1.2
PySide6==6.6.2
PySide6_Addons==6.6.2
PySide6_Essentials==6.6.2
pytest==8.1.1
python-dateutil==2.9.0.post0
python-pptx==0.6.23
pytz==2024.1
pyvista==0.43.4
pyvistaqt==0.11.0
PyYAML==6.0.1
QtPy==2.4.1
requests==2.31.0
retrying==1.3.4
rich==13.7.1
scikit-learn==1.4.1.post1
scipy==1.12.0
scooby==0.9.2
seaborn==0.13.2
shiboken6==6.6.2
six==1.16.0
stack-data==0.6.3
tenacity==8.2.3
tensorboard==2.16.2
tensorboard-data-server==0.7.2
tensorflow==2.16.1
tensorflow-io-gcs-filesystem==0.36.0
termcolor==2.4.0
threadpoolctl==3.3.0
tomli==2.0.1
traitlets==5.14.2
typing_extensions==4.10.0
urllib3==2.2.1
vtk==9.3.20230807rc0
wcwidth==0.2.13
websocket-client==1.7.0
Werkzeug==3.0.1
wrapt==1.16.0
xgboost==2.0.3
XlsxWriter==3.2.0
zipp==3.18.0
```