Pandasgui relying on deprecated Setuptools to set __version__

[__init__.py](https://github.com/user-attachments/files/25464962/__init__.py)

**Describe the bug**
At runtime, pandasgui throws the following error:
```
.venv\Lib\site-packages\pandasgui\__init__.py:2: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
from pkg_resources import get_distribution
```
I am not technical enough to submit a fix for this in terms of branching, pulling and committin on github but I believe the solution is to replace these lines in pandasgui __init__:
```
# Set version
from pkg_resources import get_distribution
__version__ = get_distribution('pandasgui').version
```

with the following code:
```
from importlib.metadata import version
__version__ = version("pandasgui")
```

This may prove problematic with pandas version < 3.8 and if this is a concern:
```
try:
from importlib.metadata import version
except ImportError:
# For Python < 3.8
from importlib_metadata import version

__version__ = version('pandasgui')
```