Redirect /schemas/latest to latest schema

[chalin]

• Fixes Is there an index for all available schema? #3256
• (Was formerly a part of List available schemas in 404 response to /schemas #3469)

Redirect test: https://deploy-preview-3475--opentelemetry.netlify.app/schemas/latest

$ curl -sI https://deploy-preview-3475--opentelemetry.netlify.app/schemas/latest | grep -E 'HTTP|loc'
HTTP/2 301 
location: /schemas/1.22.0

Note: there's a simpler way to get the latest version, by using the semconv spec version. But to do that I'll need to rework some scripts. I'll do that in a followup PR.

[chalin]

Followup issue:

• Rework semconv-spec-version scripts so version can be used in schema/latest redirect #3478