We were previously exporting DMA-BUFs when receiving the capture_output
request, and sending a done event on wlr_output.events.precommit. Instead,
export and send done on wlr_output.events.commit.
This fixes a crash that happens when a client requests a frame on a
backend that does not implement export_dmabuf.
An assertion fails with the message:
sway: types/wlr_output.c:777: wlr_output_lock_attach_render: Assertion
`output->attach_render_locks > 0' failed.
A client requesting frames in the ready callback may miss frames that
happen while it is waiting to receive the event or sending the request.
If that happens, the client will have an outdated frame for an
indefinite period. A new frame might not be scheduled for a very long
time.
With this change, clients will receive new frames immediately upon
request.
Some globals are static and it doesn't make sense to destroy them before
the wl_display. For instance, wl_compositor should be created before the
display is started and shouldn't be destroyed.
For these globals, we can simplify the code by removing the destructor
and stop keeping track of wl_resources (these will be destroyed with the
wl_display by libwayland).