otelhttp.WithClientTrace lost span when proxy can not connect

[ddatsh]

Description

otelhttp.WithClientTrace lost span when proxy can not connect

Environment

• OS: [e.g. win11]
• Architecture: [e.g. x86]
• Go Version: [e.g. 1.23.4]
• go.opentelemetry.io/contrib version: [e.g. v0.58.0]

Steps To Reproduce

1. Using this code ...

t := &http.Transport{}
t.Proxy = func(request *http.Request) (*url.URL, error) {
  // 127.0.0.1:10809 can not connect 
  return &url.URL{Scheme: "http", Host: "127.0.0.1:10809"}, nil
}

client = &http.Client{
Transport: otelhttp.NewTransport(
	t,
	otelhttp.WithClientTrace(func(ctx context.Context) *httptrace.ClientTrace {
		return otelhttptrace.NewClientTrace(ctx)
	}),
)}

client.Get("xxxxx")

2. Run ...
3. See error ...

go.opentelemetry.io\contrib\instrumentation\net\http\httptrace\otelhttptrace clienttrace.go

func (ct *clientTracer) gotConn(info httptrace.GotConnInfo) {

 ...
 ct.end("http.getconn", nil, attrs...) //  gotConn()   do not call when  127.0.0.1:10809 can not connect

now http.getconn span lost

func (ct *clientTracer) getConn(host string) {
	ct.start("http.getconn", "http.getconn", semconv.NetHostName(host))
}

Expected behavior

when 127.0.0.1:10809 works,

net/http/transport.go:1481

case r := <-w.result:
		// Trace success but only for HTTP/1.
		// HTTP/2 calls trace.GotConn itself.
		if r.pc != nil && r.pc.alt == nil && trace != nil && trace.GotConn != nil {
			info := httptrace.GotConnInfo{
				Conn:   r.pc.conn,
				Reused: r.pc.isReused(),
			}
			if !r.idleAt.IsZero() {
				info.WasIdle = true
				info.IdleTime = time.Since(r.idleAt)
			}
			trace.GotConn(info)      // will call  func (ct *clientTracer) getConn(host string) { ct.start("http.getconn",
		}