Bump actions/download-artifact from 2 to 4.1.7 in /.github/workflows

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 2 to 4.1.7.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v2...v4.1.7)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-type: direct:production
...

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

.github/workflows/basic-tests.yml

@@ -61,7 +61,7 @@ jobs:
     if: github.ref == 'refs/heads/master' && github.event_name == 'push'
     steps:
     - name: retrieve built documentation
-      uses: actions/download-artifact@v2
+      uses: actions/download-artifact@v4.1.7
       with:
         name: documentation-page
     - name: debug

.github/workflows/distribution.yml

@@ -44,7 +44,7 @@ jobs:
       uses: actions/setup-python@v4
       with:
         python-version: '3.10'
-    - uses: actions/download-artifact@v2
+    - uses: actions/download-artifact@v4.1.7
       with:
         path: ./
     - name: build pycbc for pypi