Slurmdbd_cluster fixes

[clil16]

This pull request fixes a few things in the slurmdbd_cluster.yml task and has been updated to pass ansible-lint with the production profile. The fixes are necessary to preserve the intended idempotency of the task.

Fixes

• The task 'Check for existence of cluster in db.' was returning the IP address of the ControlHost in SLURM 25.05.1 and not the cluster names as it was intended to do.
• The task 'set cluster_check_boolean' was comparing to the hardcoded string 'cluster' instead of the appropriate variable __slurm_cluster_name. The logic was also flawed since it set __cluster_not_setup to false when cluster_check.stdout == "cluster".

Environment

• SLURM 25.05.1
• ansible-lint 25.9.2 using ansible-core:2.18.9 ansible-compat:25.8.2 ruamel-yaml:0.18.15 ruamel-yaml-clib:0.2.12

Ansible Lint Output

$ ansible-lint --profile=production tasks/slurmdbd_cluster.yml 

Passed: 0 failure(s), 0 warning(s) in 1 files processed of 1 encountered. Profile 'production' was required, and it passed.