attach_test and attach_blocking timing out on Jenkins

Happened multiple times on retrying: http://139.178.82.61:8080/job/DynamoRIO-AArch64-Precommit/2360/console.

Seems to have started after the recent AArch64 hardware move: https://groups.google.com/g/dynamorio-devs/c/lSaVAoryR1E/m/xTylpzXvDAAJ?utm_medium=email&utm_source=footer.