Change the check with 200 OK for HTTP/2 200

See that we still getting the data as before: https://github.com/operator-framework/catalogd/actions/runs/12322347604/job/34395719725?pr=460

test/e2e/metrics_endpoint_test.go

@@ -87,5 +87,5 @@ func TestCatalogdMetricsExportedEndpoint(t *testing.T) {
 		"curl", "-v", "-k", "-H", "Authorization: Bearer "+token, metricsURL)
 	output, err = curlCmd.CombinedOutput()
 	require.NoError(t, err, "Error calling metrics endpoint: %s", string(output))
-	require.Contains(t, string(output), "200 OK", "Metrics endpoint did not return 200 OK")
+	require.Contains(t, string(output), "HTTP/2 200", "Metrics endpoint did not return HTTP/2 200")
 }