`my_dodrio_quota` command is not robust against filesystems unmounting

[boegel]

Every now and then, my_dodrio_quota crashes with:

2024-08-09 13:47:45,085 ERROR      LustreOperations MainThread  Failed to create the list of current mounted filesystems
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/vsc/filesystem/posix.py", line 245, in _local_filesystems
    self.localfilesystems = [[y[2], y[1], os.stat(y[1]).st_dev, y[0]] for y in currentmounts]
  File "/usr/lib/python3.6/site-packages/vsc/filesystem/posix.py", line 245, in <listcomp>
    self.localfilesystems = [[y[2], y[1], os.stat(y[1]).st_dev, y[0]] for y in currentmounts]
FileNotFoundError: [Errno 2] No such file or directory: '/run/user/0'
Traceback (most recent call last):
  File "/usr/bin/my_dodrio_quota", line 80, in <module>
    main()
  File "/usr/bin/my_dodrio_quota", line 70, in main
    filesystems = lustop.list_filesystems()
  File "/usr/lib/python3.6/site-packages/vsc/filesystem/lustre.py", line 214, in list_filesystems
    self._local_filesystems()
  File "/usr/lib/python3.6/site-packages/vsc/filesystem/posix.py", line 245, in _local_filesystems
    self.localfilesystems = [[y[2], y[1], os.stat(y[1]).st_dev, y[0]] for y in currentmounts]
  File "/usr/lib/python3.6/site-packages/vsc/filesystem/posix.py", line 245, in <listcomp>
    self.localfilesystems = [[y[2], y[1], os.stat(y[1]).st_dev, y[0]] for y in currentmounts]
FileNotFoundError: [Errno 2] No such file or directory: '/run/user/0'

It looks like it's looping over all mounted fileystems, and then statting them one by one, but some may be unmounted by the time the stat is done, leading to the crash.

$ mount
...
tmpfs on /run/user/0 type tmpfs (rw,nosuid,nodev,relatime,size=6542136k,mode=700)

[vsc40023@login55 ~]$ stat /run/user/0
stat: cannot statx '/run/user/0': No such file or directory

@kwaegema Can you take a look at this?