Deprecation warnings for CONDITIONAL_BARE_VARS


```
[DEPRECATION WARNING]: evaluating install_go_bootstrap as a bare variable, this
 behaviour will go away and you might need to add |bool to the expression in 
the future. Also see CONDITIONAL_BARE_VARS configuration toggle.. This feature 
will be removed in version 2.12. Deprecation warnings can be disabled by 
setting deprecation_warnings=False in ansible.cfg.
```