Create problematic additional file in integration test

csharp/ql/integration-tests/linux-only/standalone_dependencies_non_utf8_filename/test.py

@@ -1,3 +1,8 @@
 from create_database_utils import *
 
+path = b'\xd2abcd.cs'
+
+with open(path, 'w') as file:
+  file.write('class X { }\n')
+
 run_codeql_database_create([], lang="csharp", extra_args=["--extractor-option=buildless=true", "--extractor-option=cil=false"])