content length attributes not set when ignoreNetworkEvents is true

[arriIsHere]

What happened?

Steps to Reproduce

1. Open the examples/opentelemetry-web/examples/fetchexample
2. Start example
3. Note that the GET event has a http.response_content_length attribute
4. Add the ignoreNetworkEvents: true config to the FetchInstrumentation in the index.js file
5. Run example
6. Note that the GET event no longer has a http.response_content_length attribute

Expected Result

http.response_content_length attribute should still be present even if ignoreNetworkEvents is set to true

Actual Result

http.response_content_length is not present when ignoreNetworkEvents is set to true.

Additional Details

OpenTelemetry Setup Code

const provider = new WebTracerProvider({
  resource: new Resource({
    [SEMRESATTRS_SERVICE_NAME]: 'fetch-web-service'
  }),
  // Note: For production consider using the "BatchSpanProcessor" to reduce the number of requests
  // to your exporter. Using the SimpleSpanProcessor here as it sends the spans immediately to the
  // exporter without delay
  spanProcessors:[
    new SimpleSpanProcessor(new ConsoleSpanExporter()),
    new SimpleSpanProcessor(new OTLPTraceExporter()),
  ]
});

provider.register({
  contextManager: new ZoneContextManager(),
  propagator: new B3Propagator(),
});

registerInstrumentations({
  instrumentations: [
    new FetchInstrumentation({
      ignoreNetworkEvents: true,
      ignoreUrls: [/localhost:8090\/sockjs-node/],
      propagateTraceHeaderCorsUrls: [
        'https://cors-test.appspot.com/test',
        'https://httpbin.org/get',
      ],
      clearTimingResources: true,
    }),
  ],
});

const webTracerWithZone = provider.getTracer('example-tracer-web');

package.json

No response

Relevant log output

No response

Operating System and Version

Mac M3 Pro, macOS Sonoma 14.4

Runtime and Version

Node v18.20.4
Chrome v131.0.6778.86

[dyladan]

Looks like this wasn't tracked before https://github.com/MustafaHaddara made #4706 @MustafaHaddara is there any way you can take a look at this?