Remove xvfb and use SDL env variable instead

It turns out that xvfb and Windows don't really work together, even if it's inside of a docker.

docker-scripts/build-dockers/Dockerfile

@@ -49,8 +49,8 @@ RUN cd mgba && mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr
 FROM builder AS tester
 USER root
 RUN apt-get update && \
-    apt-get install -y --no-install-recommends xvfb pulseaudio alsa-utils libsdl2-dev \
-    libzip-dev libavcodec-dev libavfilter-dev x11-utils && \
+    apt-get install -y --no-install-recommends pulseaudio alsa-utils libsdl2-dev \
+    libzip-dev libavcodec-dev libavfilter-dev && \
     apt-get autoremove -y && apt-get clean
 WORKDIR /opt/src
 USER m2gba

docker-scripts/docker-test-rom-script

@@ -1,9 +1,7 @@
 #!/bin/pwsh
 
 "Starting Dummy services"
-Xvfb :1 -screen 0 1024x768x16 &
-$Env:DISPLAY = ":1.0"
-bash /home/m2gba/src/docker-scripts/xvfb_ready.sh
+$Env:SDL_VIDEODRIVER = "dummy"
 pulseaudio -D --exit-idle-time=-1
 pactl load-module module-null-sink sink_name=SpeakerOutput sink_properties=device.description="Dummy_Output"
 

docker-scripts/xvfb_ready.sh

@@ -1,15 +0,0 @@
-#!/bin/bash
-# Wait for Xvfb
-MAX_ATTEMPTS=120 # About 60 seconds
-COUNT=0
-echo -n "Waiting for Xvfb to be ready..."
-while ! xdpyinfo -display "${DISPLAY}" >/dev/null 2>&1; do
-  echo -n "."
-  sleep 0.50s
-  COUNT=$(( COUNT + 1 ))
-  if [ "${COUNT}" -ge "${MAX_ATTEMPTS}" ]; then
-    echo "  Gave up waiting for X server on ${DISPLAY}"
-    exit 1
-  fi
-done
-echo "  Done - Xvfb is ready!"