[8.13] [ES|QL] case only requires two parameters (#179011) (#179165)

# Backport

This will backport the following commits from `main` to `8.13`:
- [[ES|QL] case only requires two parameters
(#179011)](#179011)

<!--- Backport version: 8.9.8 -->

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

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case only requires two parameters (#179011)\n\n## Summary\r\n\r\nPart of
https://github.com/elastic/kibana/issues/177699\r\n\r\nWe had `case`
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we could consider testing these n-1 cases to prevent this kind of\r\nbug
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case only requires two parameters (#179011)\n\n## Summary\r\n\r\nPart of
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case only requires two parameters (#179011)\n\n## Summary\r\n\r\nPart of
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Marta Bondyra
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BACKPORT-->

packages/kbn-monaco/src/esql/lib/ast/definitions/functions.ts

@@ -592,7 +592,7 @@ export const evalFunctionsDefinitions: FunctionDefinition[] = [
           { name: 'condition', type: 'boolean' },
           { name: 'value', type: 'any' },
         ],
-        minParams: 3,
+        minParams: 2,
         returnType: 'any',
         examples: [
           `from index | eval type = case(languages <= 1, "monolingual", languages <= 2, "bilingual", "polyglot")`,