fix duplicate node if node has both data and ml role

[ylwu-amzn]

Description

If a node has both data and ml role, the eligible nodes will have duplicate node ids. Then deploy model will fail on the duplicate node.

Issues Resolved

[List any issues this PR will resolve]

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

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.

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (741d4da) 82.49% compared to head (174fdae) 82.50%.

Files	Patch %	Lines
...org/opensearch/ml/cluster/DiscoveryNodeHelper.java	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #1829   +/-   ##
=========================================
  Coverage     82.49%   82.50%           
- Complexity     5316     5318    +2     
=========================================
  Files           510      510           
  Lines         21446    21446           
  Branches       2202     2202           
=========================================
+ Hits          17691    17693    +2     
+ Misses         2861     2858    -3     
- Partials        894      895    +1     

Flag	Coverage Δ
ml-commons	82.50% <66.66%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.