fix: use GNU grep instead of busybox

src/script.sh

@@ -4,6 +4,20 @@
 
 set -efux -o pipefail
 
+
+## Use GNU grep, busybox grep is too slow
+. "/etc/os-release"
+DISTRO="$ID"
+
+if [ -z "$(grep --help | grep 'GNU')" ]; then
+  if [ "$DISTRO" = "alpine" ]; then
+    echo "Please install GNU grep 'apk add grep'"
+    exit 1
+  fi
+  alias grep="/usr/bin/grep"
+fi
+
+
 ## Create a temporary working folder
 mkdir -p "tmp/"
 cd "tmp/"