Asset system files (using the `.asset.blend` extension) are special and cannot
be edited like normal files. Opening them showes warnings about this. So better
not "encourage" editing these files that much.
Note that this check will result in false positives, since users may create
files with this extension. Asset system files have an extra flag stored
identifying them. Accessing that from the asset representation is a bit more
involved, probably requires changes in the asset indexer. For now keeping it
simple, the false positives are not a big deal for this convenience operator.
Pull Request: https://projects.blender.org/blender/blender/pulls/123781
Part of the brush assets project, see:
- https://projects.blender.org/blender/blender/issues/116337
- https://projects.blender.org/blender/blender/pulls/106303
56387f5be5