MacOS can't re-bind to abstract Unix Domain Socket

[pauldthomson]

Description

When running the server via go run main.go serve ..., I get the following error (after a ctrl-c and re-run):

FATAL   app/grpc.go:117 listen unix @fulcio-legacy-grpc-socket: bind: address already in use

even though the socket isn't listed with netstat.

The issue seems to be MacOS-specific as an Ubuntu VM (via lima) doesn't have the same issue.