The current ngcc lock-file strategy spawns a new process in order to
capture a potential `SIGINT` and remove the lock-file. For more
information see #35861.
Previously, this unlocker process was spawned as soon as the `LockFile`
was instantiated in order to have it available as soon as possible
(given that spawning a process is an asynchronous operation). Since the
`LockFile` was instantiated and passed to the `Executor`, this meant
that an unlocker process was spawned for each cluster worker, when
running ngcc in parallel mode. These processes were not needed, since
the `LockFile` was not used in cluster workers, but we still had to pay
the overhead of each process' own memory and V8 instance.
(NOTE: This overhead was small compared to the memory consumed by ngcc's
normal operations, but still unnecessary.)
This commit avoids the extra processes by only spawning an unlocker
process when running on the cluster master process and not on worker
processes.
PR Close#36569
66effde9f3