fix: add deploykey file for Git repo checkout

tasks/install_test_scripts.yml

@@ -19,6 +19,7 @@
     accept_hostkey: "{{ item.accept_hostkey | default(true) }}"
     single_branch: "{{ item.single_branch | default(true) }}"
     recursive: "{{ item.recursive | default(false) }}"
+    key_file: "~/.ssh/id_ed25519_deploykey"
   loop:
     # runs all the pre-/post-upgrade tests on Rosetta and SubApp servers
     - dest: "rosetta_update_test/"