Bump actions/download-artifact from 2 to 3

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 2 to 3.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v2...v3)

---
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/publish.yml

@@ -15,7 +15,7 @@ jobs:
       url: https://pypi.org/p/ft-scikit-optimize
     steps:
       - name: Download artifact
-        uses: actions/download-artifact@v2
+        uses: actions/download-artifact@v3
         with:
           name: package
 
@@ -37,7 +37,7 @@ jobs:
         python-version: [ 3.11 ]
     steps:
       - name: Download artifact
-        uses: actions/download-artifact@v2
+        uses: actions/download-artifact@v3
         with:
           name: docs