🐛 fix(base): Device selection patch for gpu-screen-recorder (#93)

## Description

Adds new `-device` argument for gpu-screen-recorder which allows
specifying a GPU to use (by `/dev/dri/cardN` path)

This fixes an issue with multi-gpu systems when device such as
`/dev/dri/card1` is passed through but gpu-screen-recorder will still
try to access `/dev/dri/card0` for capturing and failing.

Added relevant bits to `gpu_helpers.sh` to find the card path - I assume
all modern modesetting drivers will have a `/drm/` path that tells the
card number. If not, the script will fall back to gpu-screen-recorder's
own method of finding the card.

Edit: Forgot to mention patches are now copied to /tmp/ rather than
/etc/

Co-authored-by: Kristian Ollikainen <DatCaptainHorse@users.noreply.github.com>

base.Dockerfile

@@ -203,7 +203,7 @@ ENV \
     # Disable VSYNC for NVIDIA GPUs
      __GL_SYNC_TO_VBLANK=0 
 
-COPY .patches /etc/
+COPY .patches /tmp/
 
 #Build and install gpu-screen-recorder
 RUN apt-get update -y \
@@ -259,7 +259,7 @@ RUN apt-get update -y \
     && find . -maxdepth 1 -type f -name "*libnvrtc.so.*" -exec sh -c 'ln -snf $(basename {}) libnvrtc.so' \; \
     && mkdir -p /usr/local/nvidia/lib && mv -f libnvrtc* /usr/local/nvidia/lib \
     && git clone https://repo.dec05eba.com/gpu-screen-recorder && cd gpu-screen-recorder \
-    && git apply /etc/connectcheckskip.patch \
+    && git apply /tmp/connectcheckskip.patch && git apply /tmp/devicearg.patch \
     && meson setup build \
     && meson configure --prefix=/usr --buildtype=release -Dsystemd=true -Dstrip=true build \
     && ninja -C build install