editoast: add utoipa annotations for GET /health

[laggron42]

Part of #3625, #4580

/health endpoint is auto-generated by utoipa, and openapi.yaml generated accordingly.

osrdEditoastApi.ts was not changed after generation.

[codecov]

Codecov Report

Merging #4662 (e023476) into dev (611bc4c) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##                dev    #4662      +/-   ##
============================================
- Coverage     20.13%   20.12%   -0.01%     
  Complexity     2238     2238              
============================================
  Files           870      870              
  Lines         89028    89010      -18     
  Branches       2294     2294              
============================================
- Hits          17925    17916       -9     
+ Misses        69828    69819       -9     
  Partials       1275     1275              

Flag	Coverage Δ
editoast	64.49% <100.00%> (+0.05%)	⬆️

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

Files Changed	Coverage Δ
editoast/src/views/mod.rs	100.00% <100.00%> (+19.35%)	⬆️

... and 27 files with indirect coverage changes