fix: Prevent removal of existing RG tags when deploying GSA

[Kanchan-Microsoft]

Purpose

This pull request updates the tagging logic and resource dependencies in the infrastructure templates to improve tag merging and ensure correct deployment order. The most significant changes involve how tags are applied to resources and the order of dependencies for private DNS zones.

Tagging logic improvements:

• The resourceGroupTags resource in main.bicep now merges both existing resource group tags and custom tags, ensuring all relevant tags are included when deploying resources.
• The generated main.json ARM template updates the tags property to use a shallowMerge of resource group tags, user-supplied tags, and required template tags, providing a more comprehensive and flexible tagging strategy.

Resource dependency order corrections:

• The dependsOn arrays for certain resources in main.json have been reordered to ensure that private DNS zones for openAI and cognitiveServices are created in the correct sequence, which can help prevent deployment issues related to resource readiness.

Other changes:

• The Bicep template hash in main.json was updated to reflect the changes in the template.

Does this introduce a breaking change?

• Yes
• No

Golden Path Validation

• I have tested the primary workflows (the "golden path") to ensure they function correctly without errors.

Deployment Validation

• I have validated the deployment process successfully and all services are running as expected with this change.

What to Check

Verify that the following are valid

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Other Information