In 'ManageResources' and 'runResourceCommand', temporary files written to '/dev/shm' may not be cleaned up, in rare cases

[jgwest]

We've had user reports of /dev/shm running out of space due to temporary files left hanging around within the application-container of Argo CD. Within Argo CD's application-controller, the references to /dev/shm are limited to gitops-engine's TempDir in pkg/utils/io.

I've thus been auditing gitops-engine's use of /dev/shm, and discovered there are a couple (rare) cases where the temporary files that are created in /dev/shm would not be cleaned up.

#569 has been raised to fix the issue.