CI: cleanup '-scale' tests infra (#11535)

There is actually no test using this since ad6fecefa8,
so there is no reason to keep that infra in our tests scripts.

tests/cloud_playbooks/roles/packet-ci/templates/inventory.j2

@@ -3,7 +3,7 @@
 instance-{{ loop.index }} ansible_host={{instance.stdout}}
 {% endfor %}
 
-{% if mode is defined and mode in ["separate", "separate-scale"] %}
+{% if mode == "separate" %}
 [kube_control_plane]
 instance-1
 
@@ -12,7 +12,7 @@ instance-2
 
 [etcd]
 instance-3
-{% elif mode is defined and mode in ["ha", "ha-scale"] %}
+{% elif mode == "ha" %}
 [kube_control_plane]
 instance-1
 instance-2
@@ -103,5 +103,3 @@ kube_control_plane
 calico_rr
 
 [calico_rr]
-
-[fake_hosts]

tests/cloud_playbooks/roles/packet-ci/vars/main.yml

@@ -1,9 +1,7 @@
 ---
 _vm_count_dict:
   separate: 3
-  separate-scale: 3
   ha: 3
-  ha-scale: 3
   ha-recover: 3
   ha-recover-noquorum: 3
   all-in-one: 1