Remove stale json schema file.

[fuzzybinary]

What does this PR do?

Remove a stale json schema file that was no longer in use.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[codecov-commenter]

Codecov Report

Merging #1866 (5b9c518) into release/2.6.0 (e5f90cc) will decrease coverage by 0.17%.
The diff coverage is n/a.

Additional details and impacted files

@@                Coverage Diff                @@
##           release/2.6.0    #1866      +/-   ##
=================================================
- Coverage          83.62%   83.46%   -0.17%     
=================================================
  Files                470      470              
  Lines              16628    16600      -28     
  Branches            2499     2496       -3     
=================================================
- Hits               13905    13854      -51     
- Misses              2050     2065      +15     
- Partials             673      681       +8     

see 23 files with indirect coverage changes