Update Azure MySQL Server to Flexible Server

[tacu90]

Summary

This pull request updates the Azure MySQL server configuration from single-server to flexible-server in both the ARM template and the necessary Azure CLI commands.

Changes Made

1. ARM Template Update:

   • Replaced the mysql single-server configuration with mysql flexible-server.
   • Ensured all relevant parameters and configurations align with the flexible-server setup.

2. Azure CLI Commands Update:

   • Updated all Azure CLI commands to use mysql flexible-server

Reason for Changes

• Deprecation of Single Server:
  The mysql single-server is marked as retired and, since March 19, new instances cannot be created via CLI. More details can be found in the Microsoft documentation.

Testing

• Verified the deployment process using the updated ARM template to ensure a mysql flexible-server is correctly provisioned.
• Confirmed that the Azure CLI commands execute without errors

Please review these changes and let me know if any further adjustments are needed. Thank you!