fix: use flipt sdk instead deprected package

[Shaktizala]

Fixes Issue

• using sdk for flipt, instead of deprecated packages.

Changes proposed

Check List (Check all the applicable boxes)

• My code follows the code style of this project.
• My change requires changes to the documentation.
• I have updated the documentation accordingly.
• All new and existing tests passed.
• This PR does not contain plagiarized content.
• The title of my pull request is a short description of the requested changes.

Screenshots

Note to reviewers

• Majority of the files are the result of the pre-commit fixes.
• Done small code changes in /helpers/flipt/flipt.go.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.