[DOCS] Refresh screenshots with deprecated rule action variables

docs/en/observability/create-alerts.asciidoc

@@ -29,6 +29,7 @@ To create SLO rules, you must first define a new SLO via the *Create new SLO* bu
 
 [role="screenshot"]
 image::images/create-alerts-manage-rules.png[Elastic {observability} Rules page]
+// NOTE: This is an autogenerated screenshot. Do not edit it directly.
 
 NOTE: You can also centrally create and manage rules, including rules _not_ related to {observability}, from the
 {kibana-ref}/create-and-manage-rules.html[{kib} Management UI].

docs/en/observability/infrastructure-threshold-alert.asciidoc

@@ -60,6 +60,7 @@ threshold condition: `Alert`, `Warning`, or `Recovered` (a value that was once a
 
 [role="screenshot"]
 image::images/infrastructure-threshold-run-when-selection.png[Configure when an alert is triggered]
+// NOTE: This is an autogenerated screenshot. Do not edit it directly.
 
 [discrete]
 == Action variables
@@ -70,6 +71,7 @@ and selecting from a list of available variables.
 
 [role="screenshot"]
 image::images/infrastructure-threshold-alert-default-message.png[Default notification message for infrastructure threshold rules with open "Add variable" popup listing available action variables,width=600]
+// NOTE: This is an autogenerated screenshot. Do not edit it directly.
 
 [discrete]
 [[infra-alert-settings]]

docs/en/observability/metrics-threshold-alert.asciidoc

@@ -74,6 +74,7 @@ Alternatively, you can set the action frequency such that you choose how often t
 
 [role="screenshot"]
 image::images/metrics-threshold-run-when-selection.png[Configure when a rule is triggered]
+// NOTE: This is an autogenerated screenshot. Do not edit it directly.
 
 [discrete]
 == Action variables
@@ -84,6 +85,7 @@ and selecting from a list of available variables.
 
 [role="screenshot"]
 image::images/metrics-threshold-alert-default-message.png[Default notification message for metrics threshold rules with open "Add variable" popup listing available action variables,width=600]
+// NOTE: This is an autogenerated screenshot. Do not edit it directly.
 
 [discrete]
 [[metrics-alert-settings]]