fix spec snapshot endpoint

[hogesako]

Description

I fixed the snapshot specifications.

https://opensearch.org/docs/latest/api-reference/snapshots/create-snapshot/
https://github.com/opensearch-project/OpenSearch/blob/main/server/src/main/java/org/opensearch/snapshots/SnapshotInfo.java

Issues Resolved

#606

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[dblock]

Thank you! Needs some npm run lint--fix, CHANGELOG, etc, please.

[github-actions]

Changes Analysis

Commit SHA: d2165d9
Comparing To SHA: 49b7c68

API Changes

Summary

├─┬Paths
│ └─┬/_snapshot/{repository}/{snapshot}
│   └─┬GET
│     └─┬Responses
│       └─┬200
│         └─┬application/json
│           └─┬Schema
│             ├──[➕] required (29743:17)❌ 
│             ├──[➖] required (29753:17)❌ 
│             ├──[➖] required (29754:17)❌ 
│             ├──[➖] properties (29749:15)❌ 
│             ├──[➖] properties (29738:15)❌ 
│             └──[➖] properties (29746:15)❌ 
└─┬Components
  ├──[➖] schemas (55376:7)❌ 
  ├──[➖] schemas (55111:7)❌ 
  ├──[➖] schemas (55096:7)❌ 
  └─┬snapshot._common:SnapshotInfo
    ├──[➖] properties (55277:9)❌ 
    ├──[➖] properties (55251:9)❌ 
    └──[➖] properties (55259:9)❌ 

Document Element	Total Changes	Breaking Changes
paths	6	6
components	6	6

• ❌ BREAKING Changes: 12 out of 12
• Removals: 11
• Additions: 1
• Breaking Removals: 11
• Breaking Additions: 1

Report

The full API changes report is available at: https://github.com/opensearch-project/opensearch-api-specification/actions/runs/11286023729/artifacts/2043802318

API Coverage

	Before	After	Δ
Covered (%)	588 (57.59 %)	588 (57.59 %)	0 (0 %)
Uncovered (%)	433 (42.41 %)	433 (42.41 %)	0 (0 %)
Unknown	29	29	0

[github-actions]

Spec Test Coverage Analysis

Total	Tested
504	315 (62.5 %)