chore!: remove telemetry API usage (#3815)

# What does this PR do?

remove telemetry as a providable API from the codebase. This includes
removing it from generated distributions but also the provider registry,
the router, etc

since `setup_logger` is tied pretty strictly to `Api.telemetry` being in
impls we still need an "instantiated provider" in our implementations.
However it should not be auto-routed or provided. So in
validate_and_prepare_providers (called from resolve_impls) I made it so
that if run_config.telemetry.enabled, we set up the meta-reference
"provider" internally to be used so that log_event will work when
called.

This is the neatest way I think we can remove telemetry from the
provider configs but also not need to rip apart the whole "telemetry is
a provider" logic just yet, but we can do it internally later without
disrupting users.

so telemetry is removed from the registry such that if a user puts
`telemetry:` as an API in their build/run config it will err out, but
can still be used by us internally as we go through this transition.


relates to #3806

Signed-off-by: Charlie Doern <cdoern@redhat.com>

llama_stack/distributions/starter-gpu/run.yaml

@@ -10,7 +10,6 @@ apis:
 - post_training
 - safety
 - scoring
-- telemetry
 - tool_runtime
 - vector_io
 providers:
@@ -154,13 +153,6 @@ providers:
       responses_store:
         type: sqlite
         db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/starter-gpu}/responses_store.db
-  telemetry:
-  - provider_id: meta-reference
-    provider_type: inline::meta-reference
-    config:
-      service_name: "${env.OTEL_SERVICE_NAME:=\u200B}"
-      sinks: ${env.TELEMETRY_SINKS:=}
-      otel_exporter_otlp_endpoint: ${env.OTEL_EXPORTER_OTLP_ENDPOINT:=}
   post_training:
   - provider_id: huggingface-gpu
     provider_type: inline::huggingface-gpu