Update actions/download-artifact action to v4

Author: renovate[bot]

.github/workflows/test-client.yaml

@@ -55,7 +55,7 @@ jobs:
       - run: |
           mkdir -p example/generated-${{ inputs.name }}
       - name: Download Generated Client
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: example-${{ inputs.name }}-client
           path: ./
@@ -90,7 +90,7 @@ jobs:
       - run: |
           mkdir -p example/generated-${{ inputs.name }}
       - name: Download Generated Client
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: example-${{ inputs.name }}-client
           path: ./