[Build/Release] Convert linux release to produce an appimage

Ported from xenia-edge with minor adjustments to remove Qt deps.

.github/workflows/Create_release.yml

@@ -90,8 +90,8 @@ jobs:
       - name: Download Linux artifacts
         uses: actions/download-artifact@v8
         with:
-          name: xenia_canary_linux.tar.xz
-          path: artifacts
+          name: xenia_canary_linux
+          path: artifacts/linux
 
       # Uncomment when platforms are enabled:
       # - name: Download macOS artifacts
@@ -119,9 +119,9 @@ jobs:
             cd ../../..
           fi
 
-          # Linux (already tar.gz)
-          if [ -f "artifacts/xenia_canary_linux.tar.xz" ]; then
-            cp artifacts/xenia_canary_linux.tar.xz release_assets/
+          # Linux AppImage
+          if [ -f "artifacts/linux/xenia_canary_linux.AppImage" ]; then
+            cp artifacts/linux/xenia_canary_linux.AppImage release_assets/
           fi
 
           # macOS (uncomment when enabled)