Removed image references persist in Helm chart Git repository after removal from image-list

[ravikiran-talluri]

Describe the bug
When using Argo CD Image Updater with Git write-back, removing an image from the argocd-image-updater.argoproj.io/image-list annotation removes it from the Argo CD Application manifest. However, references to this image persist in the .argocd-source-.yaml file committed back to the Helm chart's Git repository.

To Reproduce

1. Annotate an Argo CD Application with the argocd-image-updater.argoproj.io/image-list annotation, including image/s.
2. Allow the Image Updater to track and update the image.
3. Remove the image from the image-list annotation in the Application manifest.
4. Observe that while the image is removed from the Application manifest, references in the .argocd-source-.yaml file in the Helm chart repository are not cleaned up

Expected behavior
The Git write-back process should fully remove references to the deleted image from the .argocd-source-.yaml file, ensuring consistency between the Application manifest and the Helm chart Git repository.

Additional context
The removed image references are not properly cleaned from .argocd-source-.yaml during Git write-back, leading to potential issues with Helm chart consistency.

Version
15.1

[chengfang]

Does this extra image element in git repo cause any harm? Currently we pass a changeList to the writer, and since the unregistered images will not be included in that changeList, so any existing images in git repo files will not be changed. We probably should also compare each existing image in git repo file against a updateableImages list to see if any image has been unregistered since last write.