add step to initialize vendors

.github/workflows/tests.yml

@@ -27,6 +27,9 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
+    - name: Initialize vendors
+      run: |
+          PowerShell.exe -ExecutionPolicy Bypass -NoLogo -NoProfile -Command "Invoke-Expression '. ''scripts\build.ps1'' -verbose'"
     - name: Testing Clink Shell
       run: |
           cmd /c vendor\init.bat /v /d /t