[8.12] [BUG][8.12-8.15] Removes the docs for the Last Alert Status Change field and updates the "About" section screenshot (backport #6369) (#6376)

(cherry picked from commit aa612e7)

Co-authored-by: Nastasha Solomon <[email protected]>

Author: mergify[bot]

docs/detections/alerts-view-details.asciidoc

@@ -94,8 +94,6 @@ The About section has the following information:
 +
 NOTE: The event renderer only displays if an event renderer exists for the alert type. Fields are interactive; hover over them to access the available actions.
 
-* **Last alert status change**: Shows the last time the alert's status was changed, along with the user who changed it.
-
 * **MITRE ATT&CK**: Provides relevant https://attack.mitre.org/[MITRE ATT&CK] framework tactics, techniques, and sub-techniques.
 
 [discrete]