ceph_mgr_module fails to run ceph

Hello!

We are deploying ceph clusters using cephadm_bootstrap Ansible module from the collection. All works fine.

Next we try to disable unused ceph modules, but failing. Module tries to run ceph binary directly on the host. But should do `cephadm shell ceph ...` instead, like `ceph_config` does it.

Ansible task:
```
- name: Disable multiple mgr modules
ceph_mgr_module:
name: "dashboard"
state: disable
```

Error message:
```
failed: [sd-vm-atda-s3-01.eu-central-2a.core-iaws.icp.corproot.net] (item=dashboard) => {"ansible_loop_var": "item", "changed": false, "cmd": "ceph -n client.admin -k /etc/ceph/ceph.client.admin.keyring --cluster ceph mgr module disable dashboard", "item": "dashboard", "msg": "[Errno 2] No such file or directory: b'ceph'", "rc": 2, "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}
```

Locate the Python implementation of ceph_mgr_module and compare its command execution with the ceph_config module. Reproduce the shown disable-dashboard task if the collection's test or example setup allows it; done means the module uses the cephadm shell path rather than requiring a host ceph binary.

Written by the indexing model from the issue text.