Disable multi-tenancy in multi-data-source tests

[cwperks]

Summary

• disable Security multi-tenancy in the multi-data-source Cypress workflow
• apply the same backend Security configuration to both local and remote OpenSearch fixtures
• remove the tenancy-only assertion from the MDS Cypress specification
• align the multi-data-source server integration suite with the non-multitenant configuration

Root cause

The multi-data-source workflow enabled both MDS and Security multi-tenancy. Data source saved objects were therefore created in the caller's tenant, while the credential lookup used the internal Dashboards user and could not find the tenant-specific object. The resulting Saved object [data-source/<id>] not found errors caused the Security MDS tests to fail consistently.

MDS and Security multi-tenancy are intended to be mutually exclusive. This change runs the MDS coverage in the supported non-multitenant configuration instead of changing Dashboards credential lookup behavior to support the invalid combination.

Validation

• multi-data-source server integration block: 6 tests passed against two local OpenSearch clusters with unmodified Dashboards core
• ESLint passed for the modified JavaScript and TypeScript tests
• Prettier passed for the modified JavaScript and TypeScript tests
• workflow YAML parsed successfully
• git diff --check passed

[github-actions]

PR Reviewer Guide 🔍

(Review updated until commit 2e84678)

Here are some key observations to aid the review process:

🧪 PR contains tests

🔒 No security concerns identified

✅ No TODO sections

🔀 No multiple PR themes

⚡ No major issues detected

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 70.45%. Comparing base (0fda68d) to head (2e84678).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2479   +/-   ##
=======================================
  Coverage   70.45%   70.45%           
=======================================
  Files         104      104           
  Lines        3198     3198           
  Branches      574      574           
=======================================
  Hits         2253     2253           
  Misses        773      773           
  Partials      172      172           

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[github-actions]

Persistent review updated to latest commit 441429e

[github-actions]

Persistent review updated to latest commit 2e84678