chore: Changing back to ubuntu-latest

We changed the integration test script to run on linux so changing back to ubuntu-latest.

Author: lahirumaramba

.github/workflows/nightly.yml

@@ -25,7 +25,7 @@ on:
 jobs:
   nightly:
 
-    runs-on: windows-latest
+    runs-on: ubuntu-latest
 
     env:
       DOTNET_SKIP_FIRST_TIME_EXPERIENCE: 1