Use set -x in script/clear-target-dir-if-larger-than (#42525)

Closes #ISSUE

Release Notes:

- N/A *or* Added/Fixed/Improved ...

script/clear-target-dir-if-larger-than

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-set -eu
+set -euxo pipefail
 
 if [[ $# -ne 1 ]]; then
     echo "usage: $0 <MAX_SIZE_IN_GB>"