minor #20450 Replaced caution directive by warning (TimoBakx)

This PR was merged into the 7.2 branch.

Discussion
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Replaced `caution` directive by `warning`

Fixes #20371

Commits
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0a3fb8d Replaced `caution` directive by `warning`

Author: wouterj

reference/forms/types/options/choice_lazy.rst.inc

@@ -24,7 +24,7 @@ will only load and render the choices that are preset as default values or
 submitted. This defers the loading of the full list of choices, helping to
 improve your form's performance.
 
-.. caution::
+.. warning::
 
     Keep in mind that when using ``choice_lazy``, you are responsible for
     providing the user interface for selecting choices, typically through a