Add replace to builder config

Author: ycombinator

cmd/otelcorecol/builder-config.yaml

@@ -93,6 +93,7 @@ replaces:
   - go.opentelemetry.io/collector/internal/fanoutconsumer => ../../internal/fanoutconsumer
   - go.opentelemetry.io/collector/internal/telemetry => ../../internal/telemetry
   - go.opentelemetry.io/collector/internal/sharedcomponent => ../../internal/sharedcomponent
+  - go.opentelemetry.io/collector/internal/testutil => ../../internal/testutil
   - go.opentelemetry.io/collector/otelcol => ../../otelcol
   - go.opentelemetry.io/collector/pdata => ../../pdata
   - go.opentelemetry.io/collector/pdata/testdata => ../../pdata/testdata