Bump actions/download-artifact from 3 to 4 (#642)

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v3...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/keycloak-scalability-benchmark.yml

@@ -200,7 +200,7 @@ jobs:
         with:
           ref: 'result-data'
 
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: summary
 

.github/workflows/rosa-run-benchmark.yml

@@ -125,7 +125,7 @@ jobs:
         with:
           ref: 'result-data'
 
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: summary
 

.github/workflows/rosa-scaling-benchmark.yml

@@ -385,7 +385,7 @@ jobs:
         with:
           ref: 'result-data'
 
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: Calculated environment conclusion