remove bids-validator pin

[sappelhoff]

the reason for the pin has been fixed:

• https://github.com/bids-standard/bids-validator/issues/2124

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.47%. Comparing base (ed75468) to head (cf1f0fc).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1322   +/-   ##
=======================================
  Coverage   97.47%   97.47%           
=======================================
  Files          40       40           
  Lines        8872     8872           
=======================================
  Hits         8648     8648           
  Misses        224      224           

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

[sappelhoff]

I have no idea why this fails with:

python: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.38' not found (required by /opt/hostedtoolcache/Python/3.12.7/x64/lib/libpython3.12.so.1.0)

There are other jobs on the same sort of specification that run without problems.