Remove unused "carrier probing"

This is effectively a revert of commit 771af49 which added a
commented-out feature for printing out carrier info of the first hop.

On one hand, I'm reluctant to remove this, because apparently this was
not added by an accident, the PR #193 explicitly speaks about a
suggestion from Dave Boertjes for this feature -- and the git history
with merges looks like this one was actually pulled in as a single
commit. On the other hand, it is apparently not used anywhere, and all
of the required information is already available in some other manner --
for example, one can easily follow the path and add these prints to the
propagation, or just walk the path manually.

Digging further, I removed some of similar print() statements in
acafc78, and then restored some commented-out print()s via ec9eb8d (also
see the discussion in #299), which were then removed by Esther in
8107dde. So my TL;DR version is that this is dead code, and that
apparently the *real* use case is having total insight into the spectrum
info along the path (e.g., #246). That should, IMHO, be handled by
proper processing of the resulting data in a nice UI.

Change-Id: I366d33f98e230f4cb60a6d4b791707f7604f8d65

gnpy/tools/cli_examples.py

@@ -237,11 +237,6 @@ def transmission_main_example(args=None):
         else:
             print(path[-1])
 
-        # print(f'\n !!!!!!!!!!!!!!!!!     TEST POINT         !!!!!!!!!!!!!!!!!!!!!')
-        # print(f'carriers ase output of {path[1]} =\n {list(path[1].carriers("out", "nli"))}')
-        # => use "in" or "out" parameter
-        # => use "nli" or "ase" or "signal" or "total" parameter
-
     if args.save_network is not None:
         save_network(network, args.save_network)
         print(f'{ansi_escapes.blue}Network (after autodesign) saved to {args.save_network}{ansi_escapes.reset}')