Add example of using loop: with when: statements (#42776)

lib/ansible/plugins/lookup/dict.py

@@ -38,6 +38,12 @@ tasks:
     debug:
       msg: "{{item.key}}: {{item.value}}"
     with_dict: {a: 1, b: 2, c: 3}
+  # Items from loop can be used in when: statements
+  - name: set_fact when alice in key
+    set_fact:
+      alice_exists: true
+    loop: "{{ lookup('dict', users) }}"
+    when: "'alice' in item.key"
 """
 
 RETURN = """