`--new-pr` with existing file leads to error even if not modified

I tried to do a `eb --new-pr *` to add new files but it failed with

> ERROR: A meaningful commit message must be specified via --pr-commit-msg when modifying/deleting files or targeting the framework repo.
> Modified: lxml-5.3.0-GCCcore-13.3.0.eb

Something must be wrong in the detection