Bump actions/upload-artifact from 2 to 4

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

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/publish.yml

@@ -60,7 +60,7 @@ jobs:
     - name: Verifiable build
       run: anchor build --verifiable
     - name: Upload artifacts
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v4
       with:
         name: verifiable-build
         path: |