[BUG] tmux showenv needs -g in tmux version 3.3a

[ztlevi]

Describe the bug
Recently, I updated my tmux to 3.3a which is the latest version from homebrew. It causes tmux showenv SSH_TTY prints nothing. I need to add -g in order to print SSH_TTY env properly.

To Reproduce
Steps to reproduce the behavior:

• Install tmux 3.3a
• try tmux showenv SSH_TTY and tmux showenv -g SSH_TTY

Expected behavior
As tmux updated it's shownenv command, we should add -g for tmux version > 3.3a

** System Info (please complete the following information):**

• OS: Linux, Ubuntu 18
• Emacs Version: 28.2
• Terminal program: Alacritty
• Any terminal multiplexers in play [GNU screen, Tmux]: tmux
• Local or remote (over SSH): ssh

Additional context
Add any other context about the problem here.

[ztlevi]

Actually this is might be a false alarm. I remove the -p and clipetty still work. But the tmux showenv SSH_TTY doesn't print anything.