Add support for Python 3.12 and 3.13 testing

## Feature Request
Add Python 3.12 and 3.13 to our GitHub Actions test matrix. Currently, we test against Python 3.9-3.11.

## Motivation
- Python 3.12 was released in October 2023
- Python 3.13 was released in ~December~ October 2024
- We should ensure compatibility with all currently released Python versions

## Known Issues to Address
1. Python 3.12 removes several deprecated unittest methods:
- `TestCase.assertEquals()` -> `assertEqual()`
- `TestCase.assertNotEquals()` -> `assertNotEqual()`
- `TestCase.assertAlmostEquals()` -> `assertAlmostEqual()`
- And others (see [Python 3.12 changelog](https://docs.python.org/3/whatsnew/3.12.html#unittest))

2. Our test suite currently uses some of these deprecated methods, particularly in:
- `tests/test_open_ephys/test_utils/test_behavior_utils.py`
- `tests/test_open_ephys/test_utils/test_stim_utils.py`

## Implementation Steps
1. Update `.github/workflows/run_dev_tests.yml` to include Python 3.12 and 3.13:
```yaml
python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
```
2. Update deprecated unittest assertions
3. Test and fix any other compatibility issues that arise