docs: add note to clarify that ngOnChanges is only called if inputs are bound (#42374)

fixes #23017

PR Close #42374

aio/content/guide/lifecycle-hooks.md

@@ -60,7 +60,7 @@ Angular executes hook methods in the following sequence. You can use them to per
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-      Called before `ngOnInit()` and whenever one or more data-bound input properties change.
+      Called before `ngOnInit()` (if the component has bound inputs) and whenever one or more data-bound input properties change.
 
       Note that if your component has no inputs or you use it without providing any inputs, the framework will not call `ngOnChanges()`.
 
@@ -79,7 +79,7 @@ Angular executes hook methods in the following sequence. You can use them to per
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-      Called once, after the first `ngOnChanges()`.
+      Called once, after the first `ngOnChanges()`. `ngOnInit()` is still called even when `ngOnChanges()` is not (which is the case when there are no template-bound inputs).
 
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