Build phar from CI

.github/workflows/workflow.yaml

@@ -16,4 +16,13 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
             php-version: '8.3'
-            tools: box
+            tools: box
+
+      - name: Build phar
+        run: box build
+
+      - name: Archive production artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: phar-build
+          path: *.phar