[BUG] Integration tests are failing in dependabot PRs

[dblock]

What is the bug?

CI/CD got stale, integration tests are failing in Dependabot PRs.

How can one reproduce the bug?

See failures in any of https://github.com/opensearch-project/opensearch-sdk-py/pulls.

What is the expected behavior?

CI/CD to be green.

[dbwiddis]

CI/CD got stale

2 issues.

1. OpenSearch is not even compiling. Offending PR merged 2 weeks ago.
2. Gradle has deprecated features. Offending PR (update to Gradle 8.20 merged 2 months ago.

FAILURE: Build completed with 2 failures.
> Task :server:compileJava FAILED
...
> Compilation failed; see the compiler error output for details.

Looks like it's set for strict javadoc checking

/home/runner/work/opensearch-sdk-py/opensearch-sdk-py/opensearch/server/src/main/java/org/opensearch/action/pagination/PaginationStrategy.java:48: error: no tag name after @
     * Utility method to get list of indices filtered as per {@param filterPredicate} and the sorted according to {@param comparator}.
                                                             ^
/home/runner/work/opensearch-sdk-py/opensearch-sdk-py/opensearch/server/src/main/java/org/opensearch/action/pagination/PaginationStrategy.java:48: error: no tag name after @
     * Utility method to get list of indices filtered as per {@param filterPredicate} and the sorted according to {@param comparator}.
                                                                                                                  ^
/home/runner/work/opensearch-sdk-py/opensearch-sdk-py/opensearch/server/src/main/java/org/opensearch/action/pagination/PaginationStrategy.java:60: error: no tag name after @
     * Utility method to get list of indices sorted as per {@param comparator}.

Those @param should probably be @link.

We may be able to work around it by adding -x javadoc to the gradle build until the above is fixed.

[dbwiddis]

This should fix 1 of 2 problems:

• [BUG] Invalid javadoc in PaginationStrategy class prevents OpenSearch compiling with javadocs OpenSearch#16374

Other possible problem is Gradle-9 incompatible features, we can add a switch to our gradle command in CI to not fail on deprecation. Let's get the java one fixed first.

[dbwiddis]

We should also use Java 17 in our integration GHA. Or maybe even 21 since we're using OpenSearch main.