chore: fix tokio-tar security vulnerability (RUSTSEC-2025-0111)

[lalitb]

Changes

Fixes security vulnerability in tokio-tar by upgrading testcontainers from 0.23.1 to 0.25.2.

Changes:

• Move testcontainers dependency from workspace to integration_test package
• Update integration_test MSRV to 1.88.0 (required by testcontainers 0.25.2)
• testcontainers 0.25.2 internally uses astral-tokio-tar instead of vulnerable tokio-tar

Impact: Published crates maintain MSRV 1.75.0. Only integration tests require Rust 1.88.0+.

Please provide a brief description of the changes here.

Merge requirement checklist

• CONTRIBUTING guidelines followed
• Unit tests added/updated (if applicable)
• Appropriate CHANGELOG.md files updated for non-trivial, user-facing changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.8%. Comparing base (2c364dd) to head (e7c2e5a).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #3222   +/-   ##
=====================================
  Coverage   80.8%   80.8%           
=====================================
  Files        128     128           
  Lines      23289   23289           
=====================================
  Hits       18821   18821           
  Misses      4468    4468           

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