Tyler Yahn

@XSAM PTAL.

@XSAM planning to merge this in an hour or two unless I hear from you otherwise.

+1 to just switching.

Migration plan: - Add the new semantic conventions, these will be used by default - Add option to turn on old metrics (in addition to the new which are default)...

> * It seems like the buckets may map to our exponential histogram. We might want to consider using that instead of a fixed-bucket histogram. ["buckets are power-of-2 sized"](https://github.com/golang/go/blob/355711821eea51c6456a31ab61d0dc2e9db034f7/src/runtime/histogram.go#L16) seems...

> * It doesn't have a Sum. I'm not sure if we can reasonably GA it without a sum. We may need to ask the Go team to add the...

Opt-in metric discussions: https://github.com/open-telemetry/opentelemetry-go-contrib/issues/6321

Specification issue tracking opt-in advice: https://github.com/open-telemetry/opentelemetry-specification/issues/4391

May not be ideal to split on type. There may be the case where a baggage span processor and log processor are needed. Instead: `go.opentelemetry.io/contrib/processors/baggagecopy` and then have `NewSpanProcessor` and...

@MadVikingGod PTAL