Don't show Inventory items with existing Min Quantity set

[Pranshu1902]

Describe the bug
On the page to set a minimum quantity for different Inventory items, the drop-down displays all the inventory items, even those which already have a minimum value set to them.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://care.coronasafe.in/facility/657c32be-d584-476c-9ce2-0412f0e7692e/inventory/min_quantity/list
2. Click on `Set Min Quantity
3. Open the drop-down for Inventory name
4. See error

Expected behavior
Only those items which don't have a minimum value set to them should be displayed in the drop-down.

Screenshots

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.