Update gearsystem.yml

.github/workflows/gearsystem.yml

 name: Gearsystem CI
 
-on: [push, pull_request]
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '0 0 * * 0'
 
 jobs:
   linux:
@@ -50,4 +54,4 @@ jobs:
       uses: microsoft/setup-msbuild@v1.0.2
     - name: msbuild
       run: msbuild Gearsystem.sln
-      working-directory: platforms/windows
\ No newline at end of file
+      working-directory: platforms/windows