Bump Jupyter Core to 5.8.1 based on CVE-2025-30167

[jesuino]

Updating Jupyter Core to address the CVE-2025-30167 (see GHSA-33p9-3p43-82vq)
The same change was made to to OpenDataHub/Elyra

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@ee658b4). Learn more about missing BASE report.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3324   +/-   ##
=======================================
  Coverage        ?   83.71%           
=======================================
  Files           ?      158           
  Lines           ?    19937           
  Branches        ?      505           
=======================================
  Hits            ?    16691           
  Misses          ?     3061           
  Partials        ?      185           

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