Delete redundant pybind workflows (#10957)

### Summary

These are redundant now given we have dedicated workflows for them:
-
[build-wheels-linux](https://github.com/pytorch/executorch/blob/9aaea316894430a6310aa48499c8df4d3ddb50bd/.github/workflows/build-wheels-linux.yml)
— builds + tests with model
-
[build-wheels-macos](https://github.com/pytorch/executorch/blob/9aaea316894430a6310aa48499c8df4d3ddb50bd/.github/workflows/build-wheels-macos.yml)
— builds + tests with model
- pybind preset in
[build-presets](https://github.com/pytorch/executorch/blob/9aaea316894430a6310aa48499c8df4d3ddb50bd/.github/workflows/build-presets.yml#L1)
— build

### Test plan

CI