Update actions/download-artifact action to v8 (#497)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -39,7 +39,7 @@ jobs:
       id-token: write
     steps:
       - name: ⤵️ Download distribution artifact
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: pypi-dist
           path: dist

.github/workflows/release.yml

@@ -20,7 +20,7 @@ jobs:
       id-token: write
     steps:
       - name: ⤵️ Download distribution artifact
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: pypi-dist
           path: dist