Container names were generated as {name}-{pid}-{counter}, where the
counter is a per-process itertools.count. This scheme breaks across CI
runs on the same host: if a prior job was killed abruptly (SIGKILL,
cancellation) its containers are left running since --rm only removes
containers on exit. A subsequent run whose worker inherits the same PID
(common in containerized CI with small PID namespaces) and reaches the
same counter value will collide with the orphaned container.
Replace pid+counter with uuid.uuid4(), which generates a random UUID,
making names unique across processes, hosts, and time without any shared
state or leaking host identifiers.
Fixes: SCYLLADB-1540
Closesscylladb/scylladb#29509
fbcfe3f88f