[environments] Do not fail if the platform cannot be reached

This makes the behaviour consistant with the local discovery of
environments.
4 jobs for 64_do_not_fail_when_listing_environment in 8 minutes and 5 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Build
passed #186202
docker-build
build_linux_36

00:02:42

55.0%
passed #186203
docker-build
build_linux_37

00:02:39

55.0%
passed #186200
macosx
build_macosx_36

00:08:05

55.0%
passed #186201
macosx
build_macosx_37

00:07:57

55.0%