nanoplot pre/post dont reach multiqc

### Description of the bug

ch_nanoplot_pre_txt (workflows/lrsomatic.nf:250) and ch_nanoplot_post_txt (:840) are never reassigned from NANOPLOT_*.out, so NanoPlot stats never reach MultiQC.

### Command used and terminal output

```console

```

### Relevant files

_No response_

### System information

_No response_