Bump elasticsearch-rest-client in /modules/elasticsearch

Bumps [elasticsearch-rest-client](https://github.com/elastic/elasticsearch) from 7.16.2 to 8.1.2.
- [Release notes](https://github.com/elastic/elasticsearch/releases)
- [Changelog](https://github.com/elastic/elasticsearch/blob/master/CHANGELOG.md)
- [Commits](elastic/elasticsearch@v7.16.2...v8.1.2)

---
updated-dependencies:
- dependency-name: org.elasticsearch.client:elasticsearch-rest-client
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

modules/elasticsearch/build.gradle

@@ -2,7 +2,7 @@ description = "TestContainers :: elasticsearch"
 
 dependencies {
     api project(':testcontainers')
-    testImplementation "org.elasticsearch.client:elasticsearch-rest-client:7.16.2"
+    testImplementation "org.elasticsearch.client:elasticsearch-rest-client:8.1.2"
     testImplementation "org.elasticsearch.client:transport:7.17.2"
     testImplementation 'org.rnorth.visible-assertions:visible-assertions:2.1.2'
 }