Zulip bots with Eio

Remove public_name/package from test and example executables

These executables are internal tests and examples that should not be
installed as public binaries.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

-6
-6
examples/dune
··· 1 1 (executable 2 - (public_name echo_bot) 3 2 (name echo_bot) 4 - (package zulip) 5 3 (libraries 6 4 zulip 7 5 zulip.bot ··· 12 10 mirage-crypto-rng.unix)) 13 11 14 12 (executable 15 - (public_name atom_feed_bot) 16 13 (name atom_feed_bot) 17 - (package zulip) 18 14 (libraries zulip zulip.bot eio_main cmdliner logs logs.fmt)) 19 15 20 16 (executable 21 - (public_name regression_test) 22 17 (name regression_test) 23 - (package zulip) 24 18 (libraries zulip zulip.bot eio_main cmdliner logs logs.fmt unix))