Remove feature-gate on 'list-syntax-themes' subcommand
Remove feature-gate on 'list-syntax-themes' subcommand

The goal is to minimize the use of feature gates in the code.

Even when syntect is not enabled in cobalt, present the
`list-syntax-themes` subcommad to the user.  Without syntect, the user
is notified that there are no themes because cobalt wasn't built with
syntax highlighting support.

Signed-off-by: Justin Charette <f8c1ccb28a9031959a9257227ce05d11006e6eca@gmail.com>

cobalt-org/cobalt.rs,cobalt-org/cobalt.rs,cobalt-org/cobalt.rs,cobalt-org/cobalt.rs