Add npm cache path to fix UI building (push images job) (#16097)

* Add npm cache path to fix UI building

* skip version switch

.github/workflows/stage.yml

@@ -85,9 +85,11 @@ jobs:
           cp ../awx-logos/awx/ui/client/assets/* awx/ui/public/static/media/
 
       - name: Setup node and npm for new UI build
-        uses: actions/setup-node@v2
+        uses: actions/setup-node@v4
         with:
           node-version: '18'
+          cache: 'npm'
+          cache-dependency-path: awx/awx/ui/**/package-lock.json
 
       - name: Prebuild new UI for awx image (to speed up build process)
         working-directory: awx

awx/ui/Makefile

@@ -87,7 +87,14 @@ ui/src/webpack: $(UI_DIR)/src/node_modules/webpack
 ## True target for ui/src/webpack.
 $(UI_DIR)/src/node_modules/webpack:
 	@echo "=== Installing webpack ==="
-	@cd $(UI_DIR)/src && n 18 && npm install webpack
+	@cd $(UI_DIR)/src && \
+	  maj=$$(node -p "process.versions.node.split('.')[0]"); \
+	  if [ "$$maj" != "18" ]; then \
+	    echo "Error: Need Node 18.x; found $$(node -v)" >&2; \
+	    exit 1; \
+	  fi; \
+	  npm install webpack
+
 
 .PHONY: clean/ui
 ## Clean ui