[8.x] [#192624] `multiple_es_nodes` (#193899) (#194001)

# Backport

This will backport the following commits from `main` to `8.x`:
- [[#192624] `multiple_es_nodes`
(#193899)](#193899)

<!--- Backport version: 9.4.3 -->

### Questions ?
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<!--BACKPORT [{"author":{"name":"Alejandro Fernández
Haro","email":"[email protected]"},"sourceCommit":{"committedDate":"2024-09-25T13:17:27Z","message":"[#192624]
`multiple_es_nodes`
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`multiple_es_nodes`
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`multiple_es_nodes`
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BACKPORT-->

Co-authored-by: Alejandro Fernández Haro <[email protected]>

packages/kbn-test/src/es/test_es_cluster.ts

@@ -189,7 +189,10 @@ export function createTestEsCluster<
     `transport.port=${transportPort ?? esTestConfig.getTransportPort()}`,
     // For multi-node clusters, we make all nodes master-eligible by default.
     ...(nodes.length > 1
-      ? ['discovery.type=zen', `cluster.initial_master_nodes=${nodes.map((n) => n.name).join(',')}`]
+      ? [
+          'discovery.type=multi-node',
+          `cluster.initial_master_nodes=${nodes.map((n) => n.name).join(',')}`,
+        ]
       : ['discovery.type=single-node']),
   ];