Reverted validate versions.

Author: Miguel Alonso Jr

utils/validate_versions.py

@@ -85,9 +85,7 @@ def set_version(
             f.write(new_contents)
 
     if csharp_version is not None:
-        # removed exp.1 tag from version strings since MLA package is a full package now
-        # package_version = f"{csharp_version}-exp.1"
-        package_version = f"{csharp_version}"
+        package_version = f"{csharp_version}-exp.1"
         if csharp_extensions_version is not None:
             # since this has never been promoted we need to keep
             # it in preview forever or CI will fail