ESQL: Declare LOOKUP JOIN as GA in docs (#129947)

* Declare LU JOIN GA in 9.1
* Align applies_to tags for sample, change_point

Co-authored-by: Liam Thompson <32779855+leemthompo@users.noreply.github.com>

docs/reference/query-languages/esql/_snippets/commands/layout/change_point.md

@@ -4,12 +4,10 @@
 The `CHANGE_POINT` command requires a [platinum license](https://www.elastic.co/subscriptions).
 :::
 
-::::{warning}
-This functionality is in technical preview and may be
-changed or removed in a future release. Elastic will work to fix any
-issues, but features in technical preview are not subject to the support
-SLA of official GA features.
-::::
+```yaml {applies_to}
+serverless: preview
+stack: preview 9.1.0
+```
 
 `CHANGE_POINT` detects spikes, dips, and change points in a metric.
 

docs/reference/query-languages/esql/_snippets/commands/layout/lookup-join.md

@@ -1,11 +1,8 @@
 ## `LOOKUP JOIN` [esql-lookup-join]
 
-::::{warning}
-This functionality is in technical preview and may be
-changed or removed in a future release. Elastic will work to fix any
-issues, but features in technical preview are not subject to the support
-SLA of official GA features.
-::::
+```yaml {applies_to}
+stack: preview 9.0.0, ga 9.1.0
+```
 
 `LOOKUP JOIN` enables you to add data from another index, AKA a 'lookup'
 index, to your {{esql}} query results, simplifying data enrichment

docs/reference/query-languages/esql/_snippets/commands/layout/sample.md

@@ -1,7 +1,8 @@
 ## `SAMPLE` [esql-sample]
 
 ```yaml {applies_to}
-stack: preview 9.1
+serverless: preview
+stack: preview 9.1.0
 ```
 
 The `SAMPLE` command samples a fraction of the table rows.

docs/reference/query-languages/esql/_snippets/lists/processing-commands.md

@@ -6,7 +6,7 @@
 * [`GROK`](../../commands/processing-commands.md#esql-grok)
 * [`KEEP`](../../commands/processing-commands.md#esql-keep)
 * [`LIMIT`](../../commands/processing-commands.md#esql-limit)
-* [preview] [`LOOKUP JOIN`](../../commands/processing-commands.md#esql-lookup-join)
+* [`LOOKUP JOIN`](../../commands/processing-commands.md#esql-lookup-join)
 * [preview] [`MV_EXPAND`](../../commands/processing-commands.md#esql-mv_expand)
 * [`RENAME`](../../commands/processing-commands.md#esql-rename)
 * [preview] [`SAMPLE`](../../commands/processing-commands.md#esql-sample)