remove knn from search request body

[amberzsy]

Description

remove knn from search request body

Issues Resolved

Closes #579 .

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[github-actions]

Changes Analysis

Commit SHA: dbff9dc
Comparing To SHA: c2c666f

API Changes

Summary

└─┬Paths
  ├─┬/_search
  │ ├─┬GET
  │ │ └─┬Requestbody
  │ │   └─┬application/json
  │ │     └─┬Schema
  │ │       └──[➖] properties (25350:15)❌ 
  │ └─┬POST
  │   └─┬Requestbody
  │     └─┬application/json
  │       └─┬Schema
  │         └──[➖] properties (25350:15)❌ 
  └─┬/{index}/_search
    ├─┬GET
    │ └─┬Requestbody
    │   └─┬application/json
    │     └─┬Schema
    │       └──[➖] properties (25350:15)❌ 
    └─┬POST
      └─┬Requestbody
        └─┬application/json
          └─┬Schema
            └──[➖] properties (25350:15)❌ 

Document Element	Total Changes	Breaking Changes
paths	4	4

• ❌ BREAKING Changes: 4 out of 4
• Removals: 4
• Breaking Removals: 4

Report

The full API changes report is available at: https://github.com/opensearch-project/opensearch-api-specification/actions/runs/10875048347/artifacts/1935961084

API Coverage

	Before	After	Δ
Covered (%)	560 (54.85 %)	560 (54.85 %)	0 (0 %)
Uncovered (%)	461 (45.15 %)	461 (45.15 %)	0 (0 %)
Unknown	25	25	0

[github-actions]

Spec Test Coverage Analysis

Total	Tested
585	290 (49.57 %)