Fix role application on Ubuntu image

[MLNW]

Bug description

The verification does not succeed on the Ubuntu image because of shell issues.

Molecule default > verify
  INFO     Running Ansible Verifier
  
  PLAY [Verify] ******************************************************************
  
  TASK [Get conda version] *******************************************************
  fatal: [miniconda-instance]: FAILED! => {"ansible_facts": {"discovered_interpreter_python": "/usr/bin/python3"}, "changed": false, "cmd": "source ~/.bashrc && conda --version", "delta": "0:00:00.003365", "end": "2022-01-04 17:52:24.861234", "msg": "non-zero return code", "rc": 127, "start": "2022-01-04 17:52:24.857869", "stderr": "/bin/sh: 1: source: not found", "stderr_lines": ["/bin/sh: 1: source: not found"], "stdout": "", "stdout_lines": []}
  
  PLAY RECAP *********************************************************************
  miniconda-instance         : ok=0    changed=0    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0

https://github.com/DAG-OS/ansible-role-miniconda/actions/runs/1654848658