Update nightly PyPI publish workflow condition

Summary:
This commit modifies the condition for publishing to PyPI in the nightly workflow. The check for a non-empty `PYPI_API_TOKEN` has been removed, allowing the publish step to execute regardless of the token's presence.

Changes:
- Updated the conditional statement in `.github/workflows/nightly-pypi.yml` for the PyPI publish step.

This change simplifies the publishing process and ensures that the workflow runs as scheduled.

Author: FindHao

.github/workflows/nightly-pypi.yml

@@ -45,7 +45,7 @@ jobs:
           twine check dist/*
 
       - name: Publish to PyPI (API token)
-        if: github.event_name == 'schedule' && secrets.PYPI_API_TOKEN != ''
+        if: github.event_name == 'schedule'
         uses: pypa/gh-action-pypi-publish@release/v1
         with:
           user: __token__