Bump actions/download-artifact from 5.0.0 to 6.0.0 (#94)

Author: dependabot[bot]

.github/workflows/pythonpackage.yml

@@ -179,7 +179,7 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install --upgrade twine
-      - uses: actions/download-artifact@v5.0.0
+      - uses: actions/download-artifact@v6.0.0
         with:
           pattern: built-*
           merge-multiple: true
@@ -198,7 +198,7 @@ jobs:
       permissions:
         id-token: write  # IMPORTANT: this permission is mandatory for trusted publishing
       steps:
-        - uses: actions/download-artifact@v5.0.0
+        - uses: actions/download-artifact@v6.0.0
           with:
             pattern: built-*
             merge-multiple: true