chore: Bump artifact-related action version

Author: xdoardo

.github/workflows/ci.yml

@@ -142,7 +142,7 @@ jobs:
           ls -lh dist/llvm.tar.xz
 
       - name: Upload Artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: ${{ matrix.target.id }}-${{ matrix.llvm_version }}
           path: dist
@@ -163,7 +163,7 @@ jobs:
 
     steps:
       - name: Download the Artifacts
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           path: artifacts