Change behavior to behaviour in docs and tests (#39392)

* Change behavior to behaviour

- use existing fact to get hash setting rather than shell task
- fix code highlighting syntax in playbooks_variables.rst

* Re-wrote intro section; this entire topic needs a clean-up/rewrite.

test/integration/targets/hash/roles/test_hash_behaviour/tasks/main.yml

@@ -1,4 +1,4 @@
-# test code for the hash variable behavior
+# test code for the hash variable behaviour
 # (c) 2014, James Cammarata <jcammarata@ansible.com>
 
 # This file is part of Ansible
@@ -16,26 +16,22 @@
 # You should have received a copy of the GNU General Public License
 # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
 
-- name: get the hash behavior env setting
-  shell: env | grep ^ANSIBLE_HASH_BEHAVIOUR'=' | cut -f2- -d'='
-  register: hash_behavior
-  # This only works with the local connection.  The way this test is run means the
-  connection: local
-  delegate_to: localhost
+- name: debug hash behaviour result
+  debug:
+    var: ansible_env.ANSIBLE_HASH_BEHAVIOUR
+    verbosity: 2
 
-
-- name: debug hash behavior result
-  debug: var=hash_behavior.stdout
-
-- name: assert hash behavior is merge or replace
+- name: assert hash behaviour is merge or replace
   assert:
     that:
-    - "hash_behavior.stdout in ('merge', 'replace')"
+      - ansible_env.ANSIBLE_HASH_BEHAVIOUR in ('merge', 'replace')
 
 - name: debug test_hash var
-  debug: var=test_hash
+  debug:
+    var: test_hash
+    verbosity: 2
 
 - name: assert the dictionary values match
   assert:
     that:
-    - "hash_behavior.stdout == 'merge' and test_hash == merged_hash or hash_behavior.stdout == 'replace' and test_hash == replaced_hash"
+      - "ansible_env.ANSIBLE_HASH_BEHAVIOUR == 'merge' and test_hash == merged_hash or ansible_env.ANSIBLE_HASH_BEHAVIOUR == 'replace' and test_hash == replaced_hash"

test/integration/targets/hash/test_hash.yml

@@ -1,4 +1,3 @@
----
 - hosts: testhost
   vars_files:
     - vars/test_hash_vars.yml
@@ -17,4 +16,6 @@
       role_vars: "this is in role vars/main.yml"
       vars_file: "this is in a vars_file"
   roles:
-  - { role: test_hash_behavior, test_hash: {'role_argument':'this is a role argument variable'} }
+  - role: test_hash_behaviour
+    test_hash:
+      role_argument: 'this is a role argument variable'