fix: fix downmerge issue - Update environment variable references for Azure SQL configuration

[Pavan-Microsoft]

Purpose

This pull request updates the configuration for Azure SQL in the scripts/06_create_agent.py script, standardizing environment variable names and improving backward compatibility. The main focus is to use AZURE_SQLDB_SERVER and AZURE_SQLDB_DATABASE as the primary environment variables, while still supporting the old variable names for compatibility.

Configuration updates for Azure SQL:

• Updated documentation and error messages to reference AZURE_SQLDB_SERVER and AZURE_SQLDB_DATABASE instead of the old SQLDB_SERVER and SQLDB_DATABASE names. [1] [2]
• Modified environment variable loading logic to prioritize AZURE_SQLDB_SERVER and AZURE_SQLDB_DATABASE, with fallback to SQLDB_SERVER and SQLDB_DATABASE for backward compatibility.

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.