Fix nodes API compatibility with OpenSearch 3.1.0+ search pipelines

OpenSearch 3.1.0 introduced a new phase_results_processors field in the
search_pipelines section of the nodes info API response. The Go client's
NodesInfoSearchPipelines struct was missing this field, causing it to be
dropped during JSON marshalling/unmarshalling. This resulted in test
failures when comparing raw JSON with parsed JSON.

Add PhaseResultsProcessors field with omitempty tag to maintain backward
compatibility with older OpenSearch versions that don't have this field.

Signed-off-by: Sean Chittenden <sean.chittenden@crowdstrike.com>

Author: sean-

CHANGELOG.md

@@ -14,6 +14,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ### Removed
 
 ### Fixed
+- Fix nodes API compatibility with OpenSearch 3.1.0+ by adding phase_results_processors field
 
 ### Security
 

opensearchapi/api_nodes-info.go

@@ -187,9 +187,10 @@ type NodesInfoAgg struct {
 
 // NodesInfoSearchPipelines is a sub type of NodesInfo containing information about search pipelines
 type NodesInfoSearchPipelines struct {
-	RequestProcessors  []NodesInfoType `json:"request_processors"`
-	ResponseProcessors []NodesInfoType `json:"response_processors"`
-	Processors         []NodesInfoType `json:"processors,omitempty"` // Deprecated field only available in 2.7.0
+	RequestProcessors      []NodesInfoType `json:"request_processors"`
+	ResponseProcessors     []NodesInfoType `json:"response_processors"`
+	PhaseResultsProcessors []NodesInfoType `json:"phase_results_processors,omitempty"` // Available in OpenSearch 3.1.0+
+	Processors             []NodesInfoType `json:"processors,omitempty"`               // Deprecated field only available in 2.7.0
 }
 
 // NodesInfoType is a sub type of NodesInfoIngest, NodesInfoSearchPipelines containing information about a type