Bump actions/upload-artifact from 6 to 7

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v6...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/publish_dev_artifact.yml

@@ -48,7 +48,7 @@ jobs:
           ls -la dist | grep .whl
 
       - name: Store dev artifacts - .tar.gz
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: libcloud-dev-tarball
           retention-days: 60
@@ -57,7 +57,7 @@ jobs:
             dist/*.tar.gz
 
       - name: Store dev artifacts - .whl
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: libcloud-dev-wheel
           retention-days: 60