Add Spomky-Labs/phpwa-demo to renovate repositories

Updated the .github/renovate-global.json to include 'Spomky-Labs/phpwa-demo' in the repositories list. This ensures that the repository will be managed by Renovate for automated dependency updates.

.github/renovate-global.json

@@ -6,5 +6,5 @@
   "onboarding": true,
   "onboardingBranch": "github-renovate/configure",
   "platform": "github",
-  "repositories": []
+  "repositories": ['Spomky-Labs/phpwa-demo']
 }