remove unnecessary empty build.gradle files

[rursprung]

Description

these have no impact, as the targets are added by the parent build.gradle. thus they do not need to exist and are currently just cluttering the workspace and confusing people trying to work in that area.

see also the discussion on opensearch-project/opensearch-build#99 for some details.

Signed-off-by: Ralph Ursprung Ralph.Ursprung@avaloq.com

Issues Resolved

n/a

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff
• Commit changes are listed out in CHANGELOG.md file (See: Changelog)

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.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/4241/
• CommitID: 4084e02

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/4242/
• CommitID: 17170ec

[rursprung]

Gradle Check (Jenkins) Run Completed with:

* **RESULT:** FAILURE ❌

* **URL:** https://build.ci.opensearch.org/job/gradle-check/4242/

* **CommitID:** [17170ec](https://github.com/opensearch-project/OpenSearch/commit/17170ec11c12bc365c930501e0215873777e5eec)

this might be a relevant failure:

FAILURE: Build completed with 2 failures.

1: Task failed with an exception.
-----------
* What went wrong:
Execution failed for task ':distribution:docker:docker-export:exportDockerImage'.
> A problem occurred starting process 'command 'docker''

however, i sadly currently don't have a linux box with docker on it (and a connection to the internet) available to test this... could somebody else maybe briefly try to run this with --info to see more details? thanks!

[dblock]

I just kicked it to see if it's transient.

Does ./gradle :distribution:docker:docker-export:exportDockerImage fail the same way for you locally?

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/4432/
• CommitID: 17170ec

[rursprung]

Does ./gradle :distribution:docker:docker-export:exportDockerImage fail the same way for you locally?

i wouldn't know, our infrastructure doesn't support having a local docker installation 😞 (and the OpenSearch gradle build doesn't support using Docker CLI with a remote docker server)

[rursprung]

Does ./gradle :distribution:docker:docker-export:exportDockerImage fail the same way for you locally?

i wouldn't know, our infrastructure doesn't support having a local docker installation 😞 (and the OpenSearch gradle build doesn't support using Docker CLI with a remote docker server)

i've now temporarily patched the gradle build to use Docker CLI, then it works. i've also raised #4883 to get a more long-term solution for this.

i can confirm that the gradle target builds just fine for me locally. so i've now rebased and pushed that again in the hopes that the jenkins build will now run through.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/5337/
• CommitID: 695b01f

[rursprung]

Gradle Check (Jenkins) Run Completed with:

* **RESULT:** FAILURE ❌

* **URL:** https://build.ci.opensearch.org/job/gradle-check/5337/

* **CommitID:** [695b01f](https://github.com/opensearch-project/OpenSearch/commit/695b01f40eb7e8ca2ec728511364c6f3cb462391)

see my comment above: in my environment this gradle target runs just fine, so this might be linux-specific. if somebody with access to a linux box (where they can build this project) could test if they can reproduce this error that'd be great, thanks! otherwise i'm a bit stuck here.

however, this is also not an important PR, it's just a minor cleanup...