Use the transport pool

If implemented, A transport from the pool with safe defaults will be used when creating an oci registry client.
This will enable using the proxy configuration.

Signed-off-by: Soule BA <bah.soule@gmail.com>
(cherry picked from commit b310a851c7)

internal/helm/registry/client.go

@@ -69,10 +69,10 @@ func newClient(credentialsFile string, tlsConfig *tls.Config, insecureHTTP bool)
 		opts = append(opts, registry.ClientOptPlainHTTP())
 	}
 	if tlsConfig != nil {
+		t := http.DefaultTransport.(*http.Transport).Clone()
+		t.TLSClientConfig = tlsConfig
 		opts = append(opts, registry.ClientOptHTTPClient(&http.Client{
-			Transport: &http.Transport{
-				TLSClientConfig: tlsConfig,
-			},
+			Transport: t,
 		}))
 	}
 	if credentialsFile != "" {