Add GitHub Action to check image upload sizes

[rahulsunil2]

Add GitHub Action to check image upload sizes

Description

This PR introduces a new GitHub Action workflow that automatically checks the size of image files (jpg, jpeg, png, gif) uploaded in pull requests. The workflow enforces a maximum file size limit of 5MB for all new or modified images. If any image exceeds this limit, the workflow will fail and provide a list of oversized images, helping to maintain repository size and ensure efficient loading of images in the project.

Key features of this workflow:

• Triggers on pull requests that modify image files
• Checks only new or modified images
• Enforces a 5MB size limit (configurable via environment variable)
• Provides clear error messages with file names and sizes for any oversized images
• Allows the workflow to pass if all images are within the size limit

References

• GitHub Actions documentation on workflow syntax
• Best practices for repository management

Review Checklist

• [x] I have clicked on "allow edits by maintainers".
• [ ] I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• [x] The correct base branch is being used, if not main
• [ ] I have added tests to validate that the change in functionality is working as expected