[8.8] [DOCS] Fix authentication types for alerting rule enable API (#…

…171807) (#172001)

# Backport

This will backport the following commits from `main` to `8.8`:
- [[DOCS] Fix authentication types for alerting rule enable API
(#171807)](#171807)

<!--- Backport version: 8.9.7 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

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Fix authentication types for alerting rule enable API
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Fix authentication types for alerting rule enable API
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Fix authentication types for alerting rule enable API
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Co-authored-by: Lisa Cawley <[email protected]>

docs/api/alerting/enable_rule.asciidoc

@@ -6,8 +6,6 @@
 
 Enable a rule.
 
-WARNING: This API supports <<token-api-authentication>> only.
-
 [NOTE]
 ====
 For the most up-to-date API details, refer to the