add missing build-time dep: libxtst-dev

Signed-off-by: Dentrax <[email protected]>

Author: Dentrax

libsdl3.yaml

@@ -26,6 +26,7 @@ environment:
       - libxkbcommon-dev
       - libxrandr-dev
       - libxss-dev
+      - libxtst-dev
       - mesa-dev
       - mesa-gbm
       - pulseaudio-dev