message: fix(tracing): Add express category to express middleware spans
  As per:
diff: @@ -111,7 +111,7 @@ function wrap(fn: Function, method: Method): (...args: any[]) => void {
  if (transaction) {
  const span = transaction.startChild({
  description: fn.name,
  - op: `middleware.${method}`,
  + op: `express.middleware.${method}`,
  });
  res.once('finish', () => {
  span.finish();
  @@ -130,7 +130,7 @@ function wrap(fn: Function, method: Method): (...args: any[]) => void {
  const transaction = res.__sentry_transaction;
  const span = transaction?.startChild({
  description: fn.name,
  - op: `middleware.${method}`,
  + op: `express.middleware.${method}`,
  });
  fn.call(this, req, res, function(this: NodeJS.Global, ...args: unknown[]): void {
  span?.finish();
  @@ -149,7 +149,7 @@ function wrap(fn: Function, method: Method): (...args: any[]) => void {
  const transaction = res.__sentry_transaction;
  const span = transaction?.startChild({
  description: fn.name,
  - op: `middleware.${method}`,
  + op: `express.middleware.${method}`,
  });
  fn.call(this, err, req, res, function(this: NodeJS.Global, ...args: unknown[]): void {
  span?.finish();
  