CI: streamline packet jobs definition

- Take advantage of `parallel:matrix` to make the jobs definition shorter
  and more readable.
- Remove helper scripts which are no longer needed
- Remove redundant indirection in the gitlab-ci pipelines definitions
  (only one user)

tests/files/ubuntu20-calico-etcd-kubeadm-upgrade-ha.yml

@@ -0,0 +1,24 @@
+---
+# Instance settings
+cloud_image: ubuntu-2004
+mode: ha
+
+# use the kubeadm etcd setting to test the upgrade
+etcd_deployment_type: kubeadm
+
+upgrade_cluster_setup: true
+
+# Currently ipvs not available on KVM: https://packages.ubuntu.com/search?suite=focal&arch=amd64&mode=exactfilename&searchon=contents&keywords=ip_vs_sh.ko
+kube_proxy_mode: iptables
+enable_nodelocaldns: false
+
+# Pin disabling ipip mode to ensure proper upgrade
+ipip: false
+calico_vxlan_mode: Always
+calico_network_backend: bird
+
+# Needed to bypass deprecation check
+ignore_assert_errors: true
+### FIXME FLORYUT Needed for upgrade job, will be removed when releasing kubespray 2.20
+calico_pool_blocksize: 24
+### /FIXME