database subnet should not be required for a pbs deployment

[egmsft]

Version

Please provide the azhop version used, this one is located in the bottom right of the homepage, or the version you checkout from.
1.0.42

In what area(s)?

/area administration
/area ansible
/area autoscaling
/area configuration
/area cyclecloud
/area documentation
/area image
/area job-scheduling
/area monitoring
/area ood
/area remote-visualization
/area user-management

Expected Behavior

When deploying azhop with pbs and an existing vnet, a database subnet should not be required since it is only used for the MySql Flexible Server for slurm job accounting.

Actual Behavior

When deploying azhop with pbs, and an existing vnet, the deployment fails because azhop is trying to look for a database subnet to create an instance of MySql Flexible server.

Steps to Reproduce the Problem

Set the following attribute in your config file:
deploy with terraform using:
queue_manager: openpbs

an existing vnet with the following subnets:
frontend
admin
netapp
ad
compute