[DOCS] Update upgrade docs for 7.7 (#54977)

docs/reference/upgrade.asciidoc

@@ -22,7 +22,7 @@ The following table shows the recommended upgrade paths to {version}.
 |{prev-major-version}
 |<<rolling-upgrades,Rolling upgrade>> to {version}
 
-|7.0–7.3
+|7.0–7.7
 a|
 . https://www.elastic.co/guide/en/elasticsearch/reference/{prev-major-version}/rolling-upgrades.html[Rolling upgrade] to {prev-major-version}
 . <<rolling-upgrades,Rolling upgrade>> to {version}