Fix .deb extraction for systems without dpkg-deb

Replace dpkg-deb -x (Debian-specific) with ar + tar for portable
.deb extraction. The script now handles .deb archives using standard
tools available on all Linux distributions.

lv2/x86_64/unpackArtifact.sh

@@ -1,7 +1,20 @@
 #!/usr/bin/bash
 
 rm -rf build/lv2_x64
-mkdir build/lv2_x64
+mkdir -p build/lv2_x64/pkg
 
-mkdir build/lv2_x64/pkg
-dpkg-deb -x lv2/x86_64/toobamp_*_amd64.deb  build/lv2_x64/pkg
+# Extract .deb using ar + tar (portable, no dpkg-deb needed)
+cd build/lv2_x64
+ar x ../../lv2/x86_64/toobamp_*_amd64.deb
+if [ -f data.tar.zst ]; then
+    tar --zstd -xf data.tar.zst -C pkg
+elif [ -f data.tar.xz ]; then
+    tar -xJf data.tar.xz -C pkg
+elif [ -f data.tar.gz ]; then
+    tar -xzf data.tar.gz -C pkg
+else
+    echo "Error: cannot find data.tar.* in the .deb package"
+    exit 1
+fi
+rm -f control.tar.* data.tar.* debian-binary
+cd "$OLDPWD"