tracing: Add otel tracer transport to all http clients (#14972)

* Fixed otelhttp client setups.

Note: This may not be the best solution as the http client is defined in many places. There should be a canoncial http client with the proper setup.

* Changelog fragment

* go mod tidy and gazelle

api/client/builder/BUILD.bazel

@@ -33,6 +33,7 @@ go_library(
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
+        "@io_opentelemetry_go_contrib_instrumentation_net_http_otelhttp//:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",
     ],
 )

api/client/builder/client.go

@@ -25,6 +25,7 @@ import (
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	log "github.com/sirupsen/logrus"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 )
 
 const (
@@ -108,7 +109,7 @@ func NewClient(host string, opts ...ClientOpt) (*Client, error) {
 		return nil, err
 	}
 	c := &Client{
-		hc:      &http.Client{},
+		hc:      &http.Client{Transport: otelhttp.NewTransport(http.DefaultTransport)},
 		baseURL: u,
 	}
 	for _, o := range opts {