[obs_pipelines] Clarify use_legacy_search_syntax only applies to logs pipelines (#3720)

Co-authored-by: ci.datadog-api-spec <packages@datadoghq.com>

Author: api-clients-generation-pipeline[bot]

.generator/schemas/v2/openapi.yaml

@@ -44118,6 +44118,7 @@ components:
             Set to `true` to continue using the legacy search syntax while migrating filter queries. After migrating all queries to the new syntax, set to `false`.
             The legacy syntax is deprecated and will eventually be removed.
             Requires Observability Pipelines Worker 2.11 or later.
+            Only applies to `logs` pipelines. This field is ignored for `metrics` pipelines.
             See [Upgrade Your Filter Queries to the New Search Syntax](https://docs.datadoghq.com/observability_pipelines/guide/upgrade_your_filter_queries_to_the_new_search_syntax/) for more information.
           type: boolean
       required:

src/main/java/com/datadog/api/client/v2/model/ObservabilityPipelineConfig.java

@@ -235,7 +235,8 @@ public ObservabilityPipelineConfig useLegacySearchSyntax(Boolean useLegacySearch
    * Set to <code>true</code> to continue using the legacy search syntax while migrating filter
    * queries. After migrating all queries to the new syntax, set to <code>false</code>. The legacy
    * syntax is deprecated and will eventually be removed. Requires Observability Pipelines Worker
-   * 2.11 or later. See <a
+   * 2.11 or later. Only applies to <code>logs</code> pipelines. This field is ignored for <code>
+   * metrics</code> pipelines. See <a
    * href="https://docs.datadoghq.com/observability_pipelines/guide/upgrade_your_filter_queries_to_the_new_search_syntax/">Upgrade
    * Your Filter Queries to the New Search Syntax</a> for more information.
    *