Modify quantizer test for k=1 to use uniform observer for scale, zero point (#81696)
### Summary
This PR modifies the first test in `test/quantization/core/experimental/test_quantizer.py` to use uniform observers to observe the calculate the scale and zero point qparams rather than hard-coding the values.
### Test Plan
Run unit tests with: `python test/quantization/core/experimental/test_quantizer.py`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81696
Approved by: https://github.com/HDCharles
