Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: PolarGoose

tests/test_meter_dumps.cpp

@@ -44,7 +44,7 @@ void run_meter_test(std::span<const uint8_t> payload,
 
   auto callback = [&](const dlms_parser::AxdrCapture& capture) {
     char obis_buf[32];
-    std::string obis_str(capture.obis.to_string(obis_buf));
+    capture.obis.to_string(obis_buf);
 
     if (capture.is_numeric()) {
       captured_floats[obis_buf] = capture.value_as_float_with_scaler_applied();