Remove microprofile-telemetry proposal

[brunobat]

The microprofile-telemetry proposal was already accepted and the related module should be removed.
See: https://github.com/eclipse/microprofile-telemetry

[brunobat]

CC @Emily-Jiang

[Emily-Jiang]

@brunobat yes, we should update this repo by removing the accepted proposals.