adapt bids-validator url

[sappelhoff]

See:

• NOTICE: Legacy validator to be migrated to bids-standard/legacy-validator bids-standard/legacy-validator#2179

We should finish:

• Getting ready for schema based bids-validator #1288

... and then retire the legacy validator.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.47%. Comparing base (d8f6109) to head (3b21490).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1334   +/-   ##
=======================================
  Coverage   97.47%   97.47%           
=======================================
  Files          40       40           
  Lines        8876     8876           
=======================================
  Hits         8652     8652           
  Misses        224      224           

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