Nextflow version update

[levje]

rbx_flow supports only DSL1, which means it doesn't work with recent versions of nextflow. To be able to properly run rbx_flow on a HCP, the appropriate nextflow version was made available under StdEnv/2020. Any nextflow version under StdEnv/2023 doesn't fit with the current implementation of rbx_flow, the versions available are:

However, using StdEnv/2020 with the most recent GPUs isn't supported anymore as it is recommended to use StdEnv/2023 or more recent.

We might need to update this flow to support recent versions of Nextflow.