Fix fiber error

[yoldas]

Closes #

Changes proposed in this pull request

• Increase DB pool size to avoid fiber error in Cucumber tests

Nope: https://github.com/sanger/sequencescape/actions/runs/26522996083/job/78118974495

Error: When the data release is never and the prevention comment is supplied failed: Mysql2::Error: This connection is in use by: #<Fiber:0x00007f588f4b4d00 (resumed)>

Instructions for Reviewers

[All PRs] - Confirm PR template filled
[Feature Branches] - Review code
[Production Merges to main]
    - Check story numbers included
    - Check for debug code
    - Check version

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.82%. Comparing base (6d117d5) to head (a58ac0c).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #5812      +/-   ##
===========================================
- Coverage    84.86%   84.82%   -0.04%     
===========================================
  Files         1492     1492              
  Lines        33936    33936              
  Branches      3613     3613              
===========================================
- Hits         28799    28786      -13     
- Misses        4286     4301      +15     
+ Partials       851      849       -2     

Flag	Coverage Δ
javascript	76.31% <ø> (ø)
ruby	84.68% <ø> (-0.05%)	⬇️

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

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.