Enable reserved variable name checks and fix violations (#12463)

* Enable reserved variable name checks and fix violations

Updated .ansible-lint configuration to skip only var-naming[pattern]
and var-naming[no-role-prefix] instead of skipping the entire var-naming rule.
This enables the check for reserved variable names.

Renamed variables that used reserved names to avoid conflicts.
Updated all references in tasks, variables, and templates.

Signed-off-by: Ali Afsharzadeh <afsharzadeh8@gmail.com>

* Rename namespace variable inside tasks instead of deleting it

Signed-off-by: Ali Afsharzadeh <afsharzadeh8@gmail.com>

* Change hosts variable to vm_hosts

Signed-off-by: Ali Afsharzadeh <afsharzadeh8@gmail.com>

* Use k8s_namespace instead of dashboard_namespace in dashboard.yml.j2 template

Signed-off-by: Ali Afsharzadeh <afsharzadeh8@gmail.com>

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Signed-off-by: Ali Afsharzadeh <afsharzadeh8@gmail.com>

.ansible-lint

@@ -12,10 +12,12 @@ skip_list:
   # (Disabled in June 2021)
   - 'role-name'
 
-  # [var-naming] "defaults/main.yml" File defines variable 'apiVersion' that violates variable naming standards
+  # [var-naming]
   # In Kubespray we use variables that use camelCase to match their k8s counterparts
   # (Disabled in June 2021)
-  - 'var-naming'
+  - 'var-naming[pattern]'
+  # Variables names from within roles in kubespray don't need role name as a prefix
+  - 'var-naming[no-role-prefix]'
 
   # [fqcn-builtins]
   # Roles in kubespray don't need fully qualified collection names