tests: a pane's status is output, so write the pty, not the input decoder

_status used `send`, which feeds slosh's input decoder -- the path a keystroke
from the outer terminal takes. An OSC arriving there is a reply addressed to
slosh, not output from the program, so the sequence never reached the pane:
the status stayed empty and all five checks compared against whatever the row
below the tab actually held, which is the next tab's label.

`raw` writes the pane's pty, where `cat` echoes the bytes back and the pane's
own terminal parses them -- the path the feature is for. test_osc5577.py has
used `raw` throughout for the same reason, and says so in a comment.

0 files changed, 0 insertions, 0 deletions