Bump actions/download-artifact from 2 to 4

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 2 to 4.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v2...v4)

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

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

.github/workflows/wheels.yaml

@@ -55,7 +55,7 @@ jobs:
           python -m pip install --upgrade pip
           pip install twine
       - name: Download sdist
-        uses: actions/download-artifact@v2
+        uses: actions/download-artifact@v4
         with:
           name: artifact
           path: dist
@@ -77,7 +77,7 @@ jobs:
       url: https://pypi.org/p/fastbencode
     steps:
       - name: Download distributions
-        uses: actions/download-artifact@v2
+        uses: actions/download-artifact@v4
         with:
           name: artifact
           path: dist