Merge pull request #267120 from teutat3s/zhf/fix-prometheus-exporter-smokeping

nixosTests.prometheus-exporters.smokeping fix test

nixos/tests/prometheus-exporters.nix

···
         wait_for_open_port(9374)
         wait_until_succeeds(
             "curl -sSf localhost:9374/metrics | grep '{}' | grep -v ' 0$'".format(
-                'smokeping_requests_total{host="127.0.0.1",ip="127.0.0.1"} '
+                'smokeping_requests_total{host="127.0.0.1",ip="127.0.0.1",source=""} '
             )
         )
         wait_until_succeeds(
             "curl -sSf localhost:9374/metrics | grep '{}'".format(
-                'smokeping_response_ttl{host="127.0.0.1",ip="127.0.0.1"}'
+                'smokeping_response_ttl{host="127.0.0.1",ip="127.0.0.1",source=""}'
             )
         )
       '';