[!281] Avoid more no op conditionals

Merge branch 'feature/more-avoiding-of-noop-conditionals' into 'master'

ref:dominic/dune-perftool By looking at the possible values of the condition.

See merge request [dominic/dune-perftool!281]

  [dominic/dune-perftool!281]: gitlab.dune-project.org/dominic/dune-perftool/merge_requests/281