render: properly release rendered buffers (#9807)

* cleanup eglSync

* properly release buffers in renderer

* add renderingDoneCallback and use it in screencopy

* use static constructor for CEGLSync

src/helpers/Monitor.cpp

@@ -3,7 +3,6 @@
 #include "../macros.hpp"
 #include "math/Math.hpp"
 #include "../protocols/ColorManagement.hpp"
-#include "sync/SyncReleaser.hpp"
 #include "../Compositor.hpp"
 #include "../config/ConfigValue.hpp"
 #include "../config/ConfigManager.hpp"
@@ -61,10 +60,6 @@ void CMonitor::onConnect(bool noRule) {
 
     g_pEventLoopManager->doLater([] { g_pConfigManager->ensurePersistentWorkspacesPresent(); });
 
-    if (output->supportsExplicit) {
-        inTimeline = CSyncTimeline::create(output->getBackend()->drmFD());
-    }
-
     listeners.frame  = output->events.frame.registerListener([this](std::any d) { onMonitorFrame(); });
     listeners.commit = output->events.commit.registerListener([this](std::any d) {
         if (true) { // FIXME: E->state->committed & WLR_OUTPUT_STATE_BUFFER