docs(catalog): CATALOG-12042 Bulk Pricing Rule API allows invalid min quantity of 1 for fixed pricing rules (#1240)

<!-- Ticket number or summary of work -->
# [CATALOG-12042]


## What changed?

* Removed incorrect information"For fixed rules, the minimum quantity
canʼt be less than two" for quantity_min param in bulk-pricing-rules

## Release notes draft
* Removed incorrect information"For fixed rules, the minimum quantity
canʼt be less than two" for quantity_min param in bulk-pricing-rules

## Anything else?
None

ping {names}


[CATALOG-12042]:
https://bigcommercecloud.atlassian.net/browse/CATALOG-12042?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Author: olysenko

reference/catalog/products_catalog.v3.yml

@@ -6147,8 +6147,7 @@ components:
           minimum: 0
           type: integer
           description: |
-            The minimum inclusive quantity of a product to satisfy this rule. Must be greater than or equal to zero. For `fixed` rules, the minimum quantity canʼt be less than two.
-            Required in /POST.
+            The minimum inclusive quantity of a product to satisfy this rule. Must be greater than or equal to zero. Required in /POST.
           example: 10
           x-required:
             - post