Fix Tmux's tpm

I can finally use tmux-fingers again!

I was getting `'~/.tmux/plugins/tpm/tpm' returned 127` when source the
tmux.conf but it was just because I'm stupid.
tmux-plugins/tpm#67 (comment)
solved the issue.

Note that this actual `-b` change is just copied from
https://github.com/tmux-plugins/tpm instructions and haven't checked if
it makes any difference.

I also took the chance to upgrade all plugins.

tmux.conf

@@ -81,4 +81,4 @@ set -g @batt_discharging_icon "<U+1F44E>"
 set -g @fingers-compact-hints 0
 
 # Initialize TMUX plugin manager (keep this line at the very bottom of tmux.conf)
-run '~/.tmux/plugins/tpm/tpm'
+run -b '~/.tmux/plugins/tpm/tpm'