Socket handle leak on Linux VMs

[dtlewis290]

Open socket handles accumulate in /proc//fd for an image running an active SqueakSource server. Open handles accumulate gradually, eventually leading to image lockup when the Linux per-process 1024 handle limit is reached. /usr/bin/ss shows an accumulation of sockets in CLOSE_WAIT status, fewer than the handles in /proc//fd list but presumably associated with TCP sessions for sockets not properly closed from the VM.

Issue observed in a 5.0-202312181441 VM, and is not present in a 5.0-202004301740 VM. Other Linux VMs later than 5.0-202312181441 are likely affected, although this has not been confirmed. See also discussions on the box-admins Slack channel.