fix(deps): bump actions/download-artifact from 5.0.0 to 6.0.0

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v5.0.0...v6.0.0)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/install.yml

@@ -47,7 +47,7 @@ jobs:
     needs: [build]
 
     steps:
-    - uses: actions/download-artifact@v5.0.0
+    - uses: actions/download-artifact@v6.0.0
       with:
         name: run.linkerd.io