C#: Remove useless imports from .NET 10 integration test script.

Author: michaelnebel

csharp/ql/integration-tests/all-platforms/dotnet_10/test.py

@@ -1,6 +1,3 @@
-import os
-import runs_on
-
 def test1(codeql, csharp):
     codeql.database.create()