tsdb/agent: use unique registry per tests
So tests can run in parallel.
@@ -39,7 +39,7 @@ func TestUnsupported(t *testing.T) {
opts := DefaultOptions()
logger := log.NewNopLogger()
- s, err := Open(logger, prometheus.DefaultRegisterer, nil, promAgentDir, opts)
+ s, err := Open(logger, prometheus.NewRegistry(), nil, promAgentDir, opts)
require.NoError(t, err)
defer func() {
require.NoError(t, s.Close())
