Fix the REST test failing randomly (`Endpoint /v1/items/type/2 (GET all)`)

[marien-probesys]

A test is failing randomly on the CI, which is quite annoying. The message is (cf. https://github.com/fusionSuite/backend/runs/7632516776):

   1) Endpoint /v1/items/type/2 (GET all)
       Get the items of the type:
     Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/home/runner/work/backend/backend/tests/RESTAPI/items/2_type-items-GET.js)
      at listOnTimeout (node:internal/timers:559:17)
      at processTimers (node:internal/timers:502:7)

Note that it may have been fixed in fusionSuite/backend#15

[ddurieux]

Defines from 2000 to 5000 ms the timout