(Feature) Improve CI (#2328)

* Use "npm ci"  rather than "npm install"
* Move UI tests before production image build
* Save zip file artefact from build

.github/workflows/pull_requests.yml

@@ -22,8 +22,7 @@ jobs:
 
       - name: Install
         run: |
-          export DETECT_CHROMEDRIVER_VERSION=true
-          npm install
+          npm ci
           npm run setheapsize
 
       - name: Lint
@@ -38,7 +37,22 @@ jobs:
         if: success()
         run: npx grunt prod
 
+      - name: Upload Build Artefact
+        if: success()
+        uses: actions/upload-artifact@v7
+        with:
+          name: zipped-build
+          path: build/prod/*.zip
+          retention-days: 5
+
+      - name: UI Tests
+        if: success()
+        run: |
+          sudo apt-get install xvfb
+          xvfb-run --server-args="-screen 0 1200x800x24" npx grunt testui
+
       - name: Set up Docker Buildx
+        if: success()
         uses: docker/setup-buildx-action@v3
 
       - name: Set up QEMU
@@ -50,8 +64,3 @@ jobs:
         uses: docker/build-push-action@v6
         with:
           platforms: linux/amd64,linux/arm64
-      - name: UI Tests
-        if: success()
-        run: |
-          sudo apt-get install xvfb
-          xvfb-run --server-args="-screen 0 1200x800x24" npx grunt testui