The `anim` data (e.g. of a VSE sequence) would store the last frame read from FFMPEG as an image buffer, increasing its refcounting and preventing it to be freed until the whole `anim` data itself gets freed. In current code, there is no reason to keep a reference to this image buffer in the `anim` data, so removing it. This may also give a few percent improvement on the memory usage of the VSE in some cases. Found while investigating #114342. Pull Request: https://projects.blender.org/blender/blender/pulls/114395