ci: update actions/upload-artifact to v4 with merge

.github/workflows/ci.yml

@@ -70,11 +70,14 @@ jobs:
           # This will also trigger "make dist" that creates the Python packages
           make aws-lambda-layer
       - name: Upload Python Packages
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
-          name: ${{ github.sha }}
+          name: artifact-build_lambda_layer
           path: |
             dist/*
+          if-no-files-found: 'error'
+          # since this artifact will be merged, compression is not necessary
+          compression-level: '0'
 
   docs:
     name: Build SDK API Doc
@@ -91,7 +94,23 @@ jobs:
           make apidocs
           cd docs/_build && zip -r gh-pages ./
 
-      - uses: actions/upload-artifact@v3.1.1
+      - uses: actions/upload-artifact@v4
+        with:
+          name: artifact-docs
+          path: |
+            docs/_build/gh-pages.zip
+          if-no-files-found: 'error'
+          # since this artifact will be merged, compression is not necessary
+          compression-level: '0'
+
+  merge:
+    name: Create Release Artifact
+    runs-on: ubuntu-latest
+    needs: [build_lambda_layer, docs]
+    steps:
+      - uses: actions/upload-artifact/merge@v4
         with:
+          # Craft expects release assets from github to be a single artifact named after the sha.
           name: ${{ github.sha }}
-          path: docs/_build/gh-pages.zip
+          pattern: artifact-*
+          delete-merged: true