Bump org.elasticsearch:rest-api-spec from 9.1.4 to 9.1.5

Bumps [org.elasticsearch:rest-api-spec](https://github.com/elastic/elasticsearch) from 9.1.4 to 9.1.5.
- [Release notes](https://github.com/elastic/elasticsearch/releases)
- [Changelog](https://github.com/elastic/elasticsearch/blob/main/CHANGELOG.md)
- [Commits](elastic/elasticsearch@v9.1.4...v9.1.5)

---
updated-dependencies:
- dependency-name: org.elasticsearch:rest-api-spec
  dependency-version: 9.1.5
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -10,7 +10,7 @@
 
     <properties>
         <!-- Main dependencies -->
-        <elasticsearch.version>9.1.4</elasticsearch.version>
+        <elasticsearch.version>9.1.5</elasticsearch.version>
         <elasticsearch-client.version>9.1.4</elasticsearch-client.version>
         <jackson.version>2.20.0</jackson.version>
         <log4j.version>2.25.2</log4j.version>