fix: Prevent config file dir created with conflicting permissions

The task for creating the system-level configuration directory with
permissions 0700 was running unconditionally, even during
container-based installations. This caused a file permission conflict
with the container mount point setup, which already created this
directory with 0755 permission, leading to two recurring changed states
on every playbook run. Adding a conditional ensures this task is now
skipped when `gitlab_runner_container_install` is true, resolving the
idempotency issue.

Author: carlfriedrich

tasks/global-setup.yml

@@ -5,6 +5,7 @@
     state: directory
     mode: "0700"
   become: "{{ gitlab_runner_system_mode }}"
+  when: not gitlab_runner_container_install
 
 - name: Ensure config.toml exists
   ansible.builtin.file: