Stop development of exporter and receiver components in this repository

[jmacd]

Now the OTel-Arrow exporter and receiver components have been copied into https://github.com/open-telemetry/opentelemetry-collector-contrib, it has been difficult to develop in this repository. We were forced to continue development here because the components were unstable (especially so in the v0.22.0 release).

When https://github.com/open-telemetry/opentelemetry-collector-contrib/pull/33518 merges, it will be an ideal time to remove the components from this repository. We will release v0.25.0 without those components and continue development in https://github.com/open-telemetry/opentelemetry-collector-contrib.