[BUG] Need to address MULTIPLE_DEFAULT_TAGS flagged in PostgreSQL Repo

[nasc17]

API Spec link

https://github.com/Azure/azure-rest-api-specs/blob/main/specification/postgresql/resource-manager/readme.md

API Spec version

2025-08-01

Describe the bug

Need to remove use of default tag once APIs reference Single Server are deprecated and removed.

Currently receiving Approved Avocado for the pre-existing issue to bypass: #39125 (comment)

Expected behavior

n/a

Actual behavior

n/a

Reproduction Steps

n/a

Environment

No response