Timestamp syscall tests occasionally fail

[FabijanC]

Description

Timestamp tests occasionally fail.

Tests known to fail (not sure if there's more):

• test_advancing_time::timestamp_syscall_set_in_future
• test_advancing_time::timestamp_syscall_contract_constructor
  • the most frequently failing timestamp test
  • CI log

Basically, waiting/sleeping for 1 second doesn't increment the time used by syscalls in Starknet contracts; the time stays the same.

Only fails on CI, ran a loop of several hundreds iterations, couldn't make it fail locally.

Mitigation attempts

Restarting the workflow helps.

Tried extending to sleeping for 1.1 s: #681

• problem persisted

Tried extending to sleeping for 1.5 s: 8f74b33

• problem persisted

Perhaps we can extend to 2 s?