The change from 1 to 8 was done without justification in the commit
message and possibly for debug purposes. Unfortunately it breaks
negotiation with the libcamera virtual pipeline, which defaults to
4 buffers.
Set the the value to 1 again as successful negotiation - even with an
unusually low number of buffers - is usually more desirable than an
error.
Fixes: 98b7dc7c0 ("gst: don't do set_caps from the pipewire callback")
(cherry picked from commit e81fb77322)