fix: test local quickemu is executable

quickget

@@ -3363,7 +3363,7 @@ function create_config() {
 # fallback to checking if quickemu is in the current directory.
 function resolve_quickemu() {   
     command -v quickemu || \
-    if [ -f "./quickemu" ]; then
+    if [ -x "./quickemu" ]; then
         echo "$(pwd)/quickemu"
     else
         echo "quickemu not found" >&2