[Slurm] Make slurmctld and slurmdbd services wait for remote file systems to be mounted before being started.

[gmarciani]

Description of changes

Make slurmctld and slurmdbd services wait for remote file systems to be mounted before being started.

Tests

• Before this change, slurmctld fails to restart on head node reboot.
• After this change, slurmctld succeeds the restart on head node reboot.
• The same change was already applied to slurmd
• We can safely assume that the same applies to slurmdbd

References

• Link to impacted open issues.
• Link to related PRs in other packages (i.e. cookbook, node).
• Link to documentation useful to understand the changes.

Checklist

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