Fixed scripts endpoints.

[dblock]

Description

• Fix response from /_scripts/painless/_execute which can only be a primitive.
• Fix request from /_scripts/painless/_execute which don't always require query.
• Fix Hit that can contain array fields with primitives (e.g. ratings_sum: [6]).
• Misc tests.

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[github-actions]

Changes Analysis

Commit SHA: 8234f33
Comparing To SHA: 4f27c67

API Changes

Summary

├─┬Paths
│ └─┬/_scripts/painless/_execute
│   ├─┬GET
│   │ └─┬Responses
│   │   └─┬200
│   │     └─┬application/json
│   │       └─┬Schema
│   │         └─┬result
│   │           ├──[➖] type (30340:23)❌ 
│   │           ├──[➕] oneOf (30341:21)
│   │           ├──[➕] oneOf (30342:21)
│   │           └──[➕] oneOf (30343:21)
│   └─┬POST
│     └─┬Responses
│       └─┬200
│         └─┬application/json
│           └─┬Schema
│             └─┬result
│               ├──[➖] type (30340:23)❌ 
│               ├──[➕] oneOf (30341:21)
│               ├──[➕] oneOf (30342:21)
│               └──[➕] oneOf (30343:21)
└─┬Components
  ├─┬_core.scripts_painless_execute___PainlessContextSetup
  │ └──[➖] required (43607:11)❌ 
  └─┬_core.search___Hit
    └─┬fields
      └──[🔀] additionalProperties (44098:33)❌ 

Document Element	Total Changes	Breaking Changes
components	2	2
paths	8	2

• ❌ BREAKING Changes: 4 out of 10
• Modifications: 1
• Removals: 3
• Additions: 6
• Breaking Removals: 3
• Breaking Modifications: 1

Report

The full API changes report is available at: https://github.com/opensearch-project/opensearch-api-specification/actions/runs/12052353134/artifacts/2244896881

API Coverage

	Before	After	Δ
Covered (%)	599 (58.67 %)	599 (58.67 %)	0 (0 %)
Uncovered (%)	422 (41.33 %)	422 (41.33 %)	0 (0 %)
Unknown	42	42	0

[github-actions]

Spec Test Coverage Analysis

Total	Tested
528	410 (77.65 %)

[nhtruong]

you can also do type: [number, string, boolean]
Non blocker