Bug: Samples file required even if empty, causing pipeline failure

[berntpopp]

Description:

The script currently requires the presence of samples.txt even if it is empty. If the file is not provided, the pipeline breaks, leading to an error.

Steps to Reproduce:

1. Run the script without providing a samples.txt file.
2. Observe that the pipeline fails with an error.

Expected Behavior:

The script should not require the samples.txt file if it is empty or should handle the absence of this file gracefully.