Intermittent test failure: dataset not found on delete

From https://github.com/alxndrsn/odk-central-backend/actions/runs/13857917454/job/38778861826#step:7:16649

```
2025-03-14T13:45:17.0449540Z ✔ should return purged entities as well
2025-03-14T13:45:17.0501273Z ::ffff:127.0.0.1 - - [14/Mar/2025:13:45:17 +0000] "POST /v1/sessions HTTP/1.1" 200 228
2025-03-14T13:45:17.0574410Z ::ffff:127.0.0.1 - - [14/Mar/2025:13:45:17 +0000] "POST /v1/projects/1/datasets HTTP/1.1" 200 185
2025-03-14T13:45:17.0691018Z ::ffff:127.0.0.1 - - [14/Mar/2025:13:45:17 +0000] "POST /v1/sessions HTTP/1.1" 200 228
2025-03-14T13:45:17.0753256Z ::ffff:127.0.0.1 - - [14/Mar/2025:13:45:17 +0000] "DELETE /v1/projects/1/datasets/people/entities/12345678-1234-4123-8234-123456789abc HTTP/1.1" 404 76
2025-03-14T13:45:17.0793288Z 1) should return only queried entities
...
2025-03-14T13:47:08.9817681Z 1 failing
2025-03-14T13:47:08.9818376Z
2025-03-14T13:47:08.9823039Z 1) datasets and entities
2025-03-14T13:47:08.9824461Z GET /datasets/:name/integrity
2025-03-14T13:47:08.9824960Z should return only queried entities:
2025-03-14T13:47:08.9825488Z Error: expected 200 "OK", got 404 "Not Found"
2025-03-14T13:47:08.9826571Z at /home/runner/work/odk-central-backend/odk-central-backend/test/integration/api/datasets.js:6131:10
2025-03-14T13:47:08.9827618Z at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
2025-03-14T13:47:08.9828659Z at async Context. (test/integration/api/datasets.js:38:3)
2025-03-14T13:47:08.9829640Z at async Object.transaction (node_modules/slonik/dist/src/connectionMethods/transaction.js:22:24)
2025-03-14T13:47:08.9830830Z at async Object.createConnection (node_modules/slonik/dist/src/factories/createConnection.js:97:18)
2025-03-14T13:47:08.9831565Z ----
2025-03-14T13:47:08.9832075Z at Test._assertStatus (node_modules/supertest/lib/test.js:252:14)
2025-03-14T13:47:08.9833098Z at /home/runner/work/odk-central-backend/odk-central-backend/node_modules/supertest/lib/test.js:308:13
2025-03-14T13:47:08.9834087Z at Test._assertFunction (node_modules/supertest/lib/test.js:285:13)
2025-03-14T13:47:08.9834819Z at Test.assert (node_modules/supertest/lib/test.js:164:23)
2025-03-14T13:47:08.9835586Z at localAssert (node_modules/supertest/lib/test.js:120:14)
2025-03-14T13:47:08.9836517Z at /home/runner/work/odk-central-backend/odk-central-backend/node_modules/supertest/lib/test.js:125:7
2025-03-14T13:47:08.9837468Z at Request.callback (node_modules/superagent/lib/node/index.js:867:3)
2025-03-14T13:47:08.9838634Z at /home/runner/work/odk-central-backend/odk-central-backend/node_modules/superagent/lib/node/index.js:1070:18
2025-03-14T13:47:08.9839781Z at IncomingMessage. (node_modules/superagent/lib/node/parsers/json.js:21:7)
2025-03-14T13:47:08.9840545Z at IncomingMessage.emit (node:events:536:35)
2025-03-14T13:47:08.9841081Z at IncomingMessage.emit (node:domain:489:12)
2025-03-14T13:47:08.9841682Z at endReadableNT (node:internal/streams/readable:1698:12)
2025-03-14T13:47:08.9842508Z at process.processTicksAndRejections (node:internal/process/task_queues:90:21)
```