Fix github ci linux build and RAG tool missing return

[Hailong-am]

Description

• Fix github actions failure for linux

/__e/node20/bin/node: /lib64/libm.so.6: version `GLIBC_2.27' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib64/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib64/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /__e/node20/bin/node)
/__e/node[20](https://github.com/opensearch-project/skills/actions/runs/12706385785/job/35419257910#step:3:21)/bin/node: /lib64/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib64/libc.so.6: version `GLIBC_2.28' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib64/libc.so.6: version `GLIBC_2.25' not found (required by /__e/node20/bin/node)

• Fix missing return for RAGTool

Related Issues

Resolves #[Issue number to be closed when this PR is merged]
#445

Check List

• New functionality includes testing.
• New functionality has been documented.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff.
• Public documentation issue/PR created.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.94%. Comparing base (2b76e3c) to head (4139780).
Report is 38 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #477      +/-   ##
============================================
+ Coverage     81.78%   81.94%   +0.15%     
- Complexity      193      281      +88     
============================================
  Files            11       15       +4     
  Lines           961     1407     +446     
  Branches        137      202      +65     
============================================
+ Hits            786     1153     +367     
- Misses          121      176      +55     
- Partials         54       78      +24     

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[opensearch-trigger-bot]

The backport to 2.x failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/skills/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/skills/backport-2.x
# Create a new branch
git switch --create backport/backport-477-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 f66c53bc78baba65536321b6b5413e76cb3574cd
# Push it to GitHub
git push --set-upstream origin backport/backport-477-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/skills/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-477-to-2.x.