Mark POTEL init overloads as obsolete prior to phasing these out #4932
Description
We should mark the method overloads for initialising OTEL using our span processor as obsolete prior to phasing these out in the next major release.
Probably we make a release some time in Q2 or Q3 where we mark various things obsolete that we're going to deprecate in v7.0.
Originally posted by @jamescrosswell in #4899 (comment)