Self-hosted runners do not ship fuse3, so the setuid repair step
failed with 'no fusermount3 in PATH' before the FUSE jobs could run.
Install the package instead of failing outright.
* ci: move the fusermount3 repair into a composite action
Three copies of the same block were already drifting apart, and the
target comes from PATH: only ever add setuid root to a root-owned,
non-symlink binary under the system bin paths, and say why otherwise.
* test: say that the process exited in the wait errors
"process exit status 1 before ... accepted connections" is missing its
verb. Also mark the SIGTERM return discarded - it fails with
os.ErrProcessDone exactly when the select below already handles it.
* ci: prefer the distro fusermount3 over escalating a shadow copy
The shadowing /usr/local/bin/fusermount3 is not root-owned either, so
setting its setuid bit would have handed root to a binary the runner
user owns - the repair now symlinks the distro one earlier in PATH and
touches nothing, keeping the in-place chmod for a root-owned binary with
no distro alternative. A setuid bit only grants root when root owns the
file, so accept an existing one only then.
* ci: run the FUSE workflows when the shared action changes
Their paths filters listed each workflow file but not the composite
action all three now call.
Chris Lu