Update build-python.yml (#14)

use correct action actions/download-artifact@v3 for pip freeze download

# Checklist

The following aspects have been respected by the author of this pull
request, confirmed by both pull request assignee **and** reviewer:

* Changelog update (necessity checked and entry added or not added
respectively)
  * [x] Pull Request Assignee
  * [x] Reviewer
* README update (necessity checked and entry added or not added
respectively)
  * [x] Pull Request Assignee
  * [x] Reviewer

.github/workflows/build-python.yml

@@ -96,7 +96,7 @@ jobs:
           name: html_unit_test
           path: unittest_results/
       - name: Download pip freeze
-        uses: pypa/gh-action-pypi-publish@release/v1
+        uses: actions/download-artifact@v3
         with:
           name: freeze
           path: freeze/
@@ -112,4 +112,4 @@ jobs:
             dist/*.whl
             freeze/pip_freeze.txt
             unittest_results/*.html
-          prerelease: ${{ !startsWith(github.ref, 'refs/tags/v') }}
+          prerelease: ${{ !startsWith(github.ref, 'refs/tags/v') }}