Make changes to LFK script

What does this MR do and why?

I noticed that our current script to generate loose foreign keys wasn't working as expected due to the new guidelines around migrations introduced in !133865 (merged), which are

• Migration class is now 2.2
• milestone is mandatory in the migration.

The script has been modified to include these 2 details, and the script works as expected, generating the following migration file after the change:

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.