set -x in build_apple_frameworks.sh (#9326)

This causes commands to be echoed as they are executed, making it easier
to track progress in CI.

Author: swolchok

scripts/build_apple_frameworks.sh

@@ -5,7 +5,7 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
-set -euo pipefail
+set -euxo pipefail
 
 SOURCE_ROOT_DIR=""
 OUTPUT="cmake-out"