Regenerate GitHub Actions workflow

Executed command: sbt githubWorkflowGenerate

Author: scala-steward

.github/workflows/ci.yml

@@ -152,7 +152,7 @@ jobs:
         uses: sbt/setup-sbt@v1
 
       - name: Download target directories (2.12.20)
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v5
         with:
           name: target-${{ matrix.os }}-2.12.20-${{ matrix.java }}