chore(deps): update actions/download-artifact action to v6

Author: renovate[bot]

.github/workflows/publish_pypi_prod.yml

@@ -26,7 +26,7 @@ jobs:
     steps:
       # Download artifacts from the build job
       - name: Download Artifacts
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           name: dist
           path: dist

.github/workflows/publish_pypi_test.yml

@@ -23,7 +23,7 @@ jobs:
     steps:
       # Download artifacts from the build job
       - name: Download Artifacts
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           name: dist
           path: dist