`splunkchi`: Support `github.com/go-chi/chi/v5`

[pellared]

https://github.com/go-chi/chi released v5 some time ago which we should support.

We want to use v5 too. Please support it.

[pellared]

You can consider using https://pkg.go.dev/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp and use its RouteTag option or https://pkg.go.dev/github.com/riandyrn/otelchi.

You can also take a look at open-telemetry/opentelemetry-go-contrib#4017 for inspiration how otelhttp could be used with github.com/go-chi/chi/v5