Add support for linux riscv64 platform

[kxxt]

Description

This PR adds support for linux riscv64 platform.

Cross building on x86_64 linux should be fine.
Building directly on riscv64 linux requires user to bring their own protoc executable because the maven repository does not ship prebuilt protoc executables for riscv64.

Related Issues

Resolves #2341

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

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[github-actions]

❌ Gradle check result for 46d7454: null

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[kxxt]

It appears that the Jenkins CI is successful but github workflow reports it as unsuccessful because jq failed to parse the response: https://github.com/opensearch-project/OpenSearch/actions/runs/14744106685/job/41388124137?pr=18156#step:7:635

I am not sure what's going on here.

[peterzhuamazon]

Re-triggered, force merge sometimes can mess up the gradle check logic.

[peterzhuamazon]

Seems like cross-compile from x86_64 is available then core is fine.
k-NN/PA unlikely support this, more so for knn as it has native code.

[github-actions]

✅ Gradle check result for 46d7454: SUCCESS

[codecov]

Codecov Report

Attention: Patch coverage is 88.88889% with 1 line in your changes missing coverage. Please review.

Project coverage is 72.49%. Comparing base (a6724d3) to head (5f52ee0).
Report is 11 commits behind head on main.

Files with missing lines	Patch %	Lines
.../java/org/opensearch/gradle/VersionProperties.java	50.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #18156      +/-   ##
============================================
- Coverage     72.53%   72.49%   -0.04%     
- Complexity    67207    67253      +46     
============================================
  Files          5476     5476              
  Lines        310436   310445       +9     
  Branches      45121    45121              
============================================
- Hits         225179   225065     -114     
- Misses        66894    67089     +195     
+ Partials      18363    18291      -72     

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[reta]

LGTM, thank you @kxxt , could you please resolve the conflicts? thank you

[kxxt]

LGTM, thank you @kxxt , could you please resolve the conflicts? thank you

Thanks! I have resolved the conflict.

[kxxt]

Looks like the CI is experiencing some network problem: https://github.com/opensearch-project/OpenSearch/actions/runs/14754049968/job/41419085283?pr=18156#step:3:14

[github-actions]

✅ Gradle check result for 5f52ee0: SUCCESS

[reta]

Thank you @kxxt , @peterzhuamazon anything from your side?

[peterzhuamazon]

Thank you @kxxt , @peterzhuamazon anything from your side?

Since this only exist in core not for bundle, I have no issues with the merge.

[peterzhuamazon]

And I would say remove the backport 3.0 label so that it will only affect starting 3.1.0.

[reta]

@andrross @peterzhuamazon seems like approval check is broken ... :(

[peternied]

@peterzhuamazon Looks like the Minimum approval count is still expected, can you update the branch protections settings to remove it?

[peterzhuamazon]

@peterzhuamazon Looks like the Minimum approval count is still expected, can you update the branch protections settings to remove it?

Checking.

[peterzhuamazon]

Hi @andrross @reta @peternied I have removed that check from every branch rule, then enable require code owner review for each.

Thanks.