remove default from delegate_facts to inherit (#45492)

* remove default from delegate_facts to inherit

fixes #45456

* test delegate_facts

* added note about inheritance and defaults

* yamllint

test/integration/targets/delegate_to/delegate_facts_block.yml

@@ -0,0 +1,25 @@
+- hosts: testhost
+  gather_facts: false
+  tasks:
+    - name: set var to delegated host directly
+      set_fact: qq1=333
+      delegate_facts: true
+      delegate_to: localhost
+
+    - name: ensure qq1 exists in localhost but not in testhost
+      assert:
+        that:
+            - qq1 is undefined
+            - "'qq1' in hostvars['localhost']"
+
+    - name: set var to delegated host via inheritance
+      block:
+        - set_fact: qq2=333
+      delegate_facts: true
+      delegate_to: localhost
+
+    - name: ensure qq2 exists in localhost but not in testhost
+      assert:
+        that:
+            - qq2 is undefined
+            - "'qq2' in hostvars['localhost']"

test/integration/targets/delegate_to/runme.sh

@@ -10,3 +10,5 @@ ansible-playbook test_loop_control.yml -v "$@"
 ansible-playbook test_delegate_to_loop_randomness.yml -v "$@"
 
 ansible-playbook delegate_and_nolog.yml -v "$@"
+
+ansible-playbook delegate_facts_block.yml -v "$@"