fix: check if builder already exists

Author: opajonk

scripts/create_builder.sh

@@ -1,4 +1,8 @@
 #!/usr/bin/env bash
 set -euxo pipefail
 
-docker buildx create --name multiarch --driver docker-container --use
+if ! docker buildx inspect multiarch &>/dev/null; then
+  docker buildx create --name multiarch --driver docker-container --use
+else
+  docker buildx use multiarch
+fi