Upgrade GitHub action artifacts upload-artifact & download-artifact t…

…o v4 (#53)

Since upload-artifact@v3 & download-artifact@v3 are not going to be usable from January 30th, 2025, upgrade them to v4.

Ref: https://astronomer.slack.com/archives/C07DCAVK7TR/p1736358249600619

related: astronomer/oss-integrations-private#64

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Build source distribution
         run: python -m build
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
           name: artifacts
           path: dist/*
@@ -31,7 +31,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: artifacts
           path: dist