BE | removing pagination

Summary

Pagination will be implemented in vets-website. So we need to remove the pagination in vets-api

[x] I fixed|updated|added unit tests and integration tests for each feature (if applicable).
[x] No error nor warning in the console.
[x] Events are being sent to the appropriate logging solution
[x] Documentation has been updated (link to documentation)
[x] No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
[x] Feature/bug has a monitor built into Datadog (if applicable)
[x] If app impacted requires authentication, did you login to a local build and verify all authenticated routes work as expected