fix: simplify check for ACI deployment in custom deployment

[Ragini-Microsoft]

Purpose

This pull request simplifies the deployment logic in the azure_custom.yaml file by removing unnecessary checks when determining if this is the first deployment. The main change is that the script now only checks for the existence of the AZURE_CONTAINER_REGISTRY_NAME environment variable, rather than also checking the value of IMAGE_TAG.

Deployment script simplification:

• Removed the additional check for IMAGE_TAG being not equal to 'latest' in both the PowerShell and Bash deployment hooks, so the script now only checks for the absence of AZURE_CONTAINER_REGISTRY_NAME to determine if this is the first deployment. [1] [2]

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.