feat(capture/linux): add KWin direct screencast capture method (#5009)

Co-authored-by: Ramalama2 <6314556+Ramalama2@users.noreply.github.com>

scripts/linux_build.sh

@@ -578,6 +578,7 @@ function run_step_cmake() {
     "-DSUNSHINE_ASSETS_DIR=share/sunshine"
     "-DSUNSHINE_EXECUTABLE_PATH=/usr/bin/sunshine"
     "-DSUNSHINE_ENABLE_DRM=ON"
+    "-DSUNSHINE_ENABLE_KWIN=ON"
     "-DSUNSHINE_ENABLE_PORTAL=ON"
     "-DSUNSHINE_ENABLE_WAYLAND=ON"
     "-DSUNSHINE_ENABLE_X11=ON"