chore(otel): silence otelsdk warnings across build paths

The build-env images configure an OTel exporter, but otelsdk isn't installed,
so pak's otel instrumentation logs 'no package called otelsdk' on every run.
OTEL_SDK_DISABLED is ignored by the R otel package; it gates on
OTEL_R_<SIGNAL>_EXPORTER. Set traces/logs/metrics to 'none' in build-one and
every .crow build workflow so the R otel providers are clean no-ops, without
disabling OTel for any non-R tooling.

.crow/process-updates.yaml

@@ -158,6 +158,9 @@ steps:
     image: reg.devxy.io/rpkgs/build-env-${IMG}
     pull: true
     environment:
+      OTEL_R_TRACES_EXPORTER: none
+      OTEL_R_LOGS_EXPORTER: none
+      OTEL_R_METRICS_EXPORTER: none
       RED_HAT_DEV_PW:
         from_secret: RED_HAT_DEV_PW
       B2_S3_ACCESS_KEY:
@@ -230,6 +233,9 @@ steps:
   - name: Purge CDN cache
     image: reg.devxy.io/docker.io/library/alpine:3.24
     environment:
+      OTEL_R_TRACES_EXPORTER: none
+      OTEL_R_LOGS_EXPORTER: none
+      OTEL_R_METRICS_EXPORTER: none
       BUNNYNET_API_KEY:
         from_secret: BUNNYNET_API_KEY
       SUBDOMAIN1: 'cran.devxy.io'