Cluster creation fails if detaching HEAD

Created by: NotTheEvilOne

The following error occurs if git checkout tags/<something> has been used (as an example):

openstack_compute_instance_v2.mgmtcluster_server (remote-exec): /tmp/terraform_1721514282.sh: 2: Syntax error: "(" unexpected
╷
│ Error: remote-exec provisioner error
│ 
│   with openstack_compute_instance_v2.mgmtcluster_server,
│   on mgmtcluster.tf line 157, in resource "openstack_compute_instance_v2" "mgmtcluster_server":
│  157:   provisioner "remote-exec" {
│ 
│ error executing "/tmp/terraform_1721514282.sh": Process exited with status 2
╵

The file mentioned has the following content:

#!/bin/sh
/tmp/get_k8s_git.sh https://github.com/SovereignCloudStack/k8s-cluster-api-provider.git (HEAD detached at v4.0.0)
/home/ubuntu/bin/bootstrap.sh

Issue is caused by terraform/Makefile: GITBRANCH=$(shell git branch | grep '^*' | $(SED) 's/^* //')