Fix creation of hpctests directory

The hpctests role creates a directory that is user-owned and group-owned
by hpctests_user, which defaults to ansible_user. However, this group is
not guaranteed to exist, especially in LDAP environments where groups
dedicated to a single user are often not used.

Support customising the value via the hpctests_group variable, while
still defaulting to hpctests_user.

Author: priteau

ansible/roles/hpctests/defaults/main.yml

@@ -1,5 +1,6 @@
 ---
 hpctests_user: "{{ ansible_user }}"
+hpctests_group: "{{ ansible_user }}"
 hpctests_rootdir: "/home/{{ hpctests_user }}/hpctests"
 hpctests_pre_cmd: ''
 hpctests_pingmatrix_modules: [gnu12 openmpi4]

ansible/roles/hpctests/tasks/setup.yml

@@ -26,7 +26,7 @@
     path: "{{ hpctests_rootdir }}"
     state: directory
     owner: "{{ hpctests_user }}"
-    group: "{{ hpctests_user }}"
+    group: "{{ hpctests_group }}"
 
 - name: Set fact for UCX_NET_DEVICES
   set_fact: