Change python-publish to only run when changes happen to package source code

[yemeen]

python-publish workflow shouldn't run when source code doesn't change.

Description

only runs on changes to ect/, setup.py, pyproject.toml.

Motivation and Context

allows branches to merge even if version number isn't bumped for non-package related changes

Types of changes

• [ x] Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• My code follows the code style of this project. (make clean)
• My change requires a change to the documentation.
• I have updated the documentation accordingly. (make html)
• I have incremented the version number in the pyproject.toml file.
• I have added tests to cover my changes.
• All new and existing tests passed. (make tests)

[lizliz]

Looks good!