remove ending slash from routers

[tony-nyagah]

What does this PR do?

This PR removes trailing slashes on route definitions because it’s good hygiene to keep trailing slashes off paths, mainly because it can confuse tooling that uses the specification for generating code, mocking or other applications. Some tools will get confused, some tools won’t care.
Contributes to this issue: hotosm#219

The Rate My OpenAPI score improved after doing this:
Before: https://ratemyopenapi.com/report/a6fd4fed-ec6c-42e4-abca-34c10309f305
After: https://ratemyopenapi.com/report/39a8ec60-23d3-4113-8494-f98ed2fa74ef

Considerations

The trailing slashes have no negative effect when removed in the FastAPI code: fastapi/fastapi#9328

How to test?

• Clone the repo.
• Install by following the steps in docs/src/installation/docker.md or docs/src/installation/docker.md.
• Run locally and view routes at http://localhost:8000/v1/docs