[godot] Use official Ubuntu repo for deps.

.github/workflows/spine-godot.yml

@@ -53,6 +53,9 @@ jobs:
       - name: Build Godot artifact
         shell: bash
         run: |          
+          sudo rm -f /etc/apt/sources.list.d/*
+          sudo cp -f spine-godot/build/sources.lst /etc/apt/sources.list
+          sudo apt-get update
           sudo apt-get install build-essential scons pkg-config libx11-dev libxcursor-dev libxinerama-dev libgl1-mesa-dev libglu-dev libasound2-dev libpulse-dev libudev-dev libxi-dev libxrandr-dev
           ./spine-godot/build/setup.sh $GODOT_TAG false
           ./spine-godot/build/build.sh release_debug
@@ -142,6 +145,9 @@ jobs:
 
       - name: Build Godot artifact
         run: |
+          sudo rm -f /etc/apt/sources.list.d/*
+          sudo cp -f spine-godot/build/sources.lst /etc/apt/sources.list
+          sudo apt-get update
           sudo apt-get install build-essential scons pkg-config libx11-dev libxcursor-dev libxinerama-dev libgl1-mesa-dev libglu-dev libasound2-dev libpulse-dev libudev-dev libxi-dev libxrandr-dev
           ./spine-godot/build/setup.sh $GODOT_TAG false
           ./spine-godot/build/build-templates.sh linux