Fix metadata migrate get version

[AndreKurait]

Description

Fix double trailing slash in getClusterVersion since rest client was adding "/" which was causing 400 Bad Request in AWS against OS 2.15 (Note, was not causing issues in containers or other versions)

Bug Introduced in #922

• Category: Bug Fix
• Why these changes are required? AWS Opensearch Service Support
• What is the old behavior before changes and new behavior after changes? Any Metadata Migrations to AWS Opensearch Service failed for this getVersionCall since Metadata Migration with user centric output #922

Issues Resolved

Is this a backport? If so, please add backport PR # and/or commits #

Testing

Testing in AWS and unit tests added

Check List

• New functionality includes testing
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented
• 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.

[AndreKurait]

Recreating #1001 as codecov was failing

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.16%. Comparing base (6c32e29) to head (494958c).
Report is 2 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1003      +/-   ##
============================================
- Coverage     80.17%   80.16%   -0.01%     
+ Complexity     2721     2720       -1     
============================================
  Files           370      370              
  Lines         13622    13622              
  Branches        938      938              
============================================
- Hits          10921    10920       -1     
- Misses         2130     2131       +1     
  Partials        571      571              

Flag	Coverage Δ
gradle-test	78.17% <100.00%> (-0.01%)	⬇️
python-test	89.90% <ø> (ø)

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.

[chelma]

LGTM (again)