test: assert telemetry is inert when nothing is configured (#14739)

* test: assert telemetry is inert when nothing is configured

Every Langflow install runs with no OpenTelemetry endpoint set, so an operator
who has not opted in is entitled to assume nothing is produced and nothing is
sent. A regression there leaks to whatever happens to be listening rather than
failing loudly.

Three claims, because none implies the others: the global provider stays the
API no-op, no exporter threads are alive, and nothing arrives at a listener on
the OTLP default ports. Only the first was covered before, and a no-op provider
does not prove some other import path did not start an exporter of its own, nor
that no hardcoded default endpoint is in use.

The first version of the thread assertion was vacuous. The probe called
shutdown before enumerating threads, so it reported an empty list even with
telemetry fully live. Enumerating first, an active process reports
OtelBatchLogRecordProcessor, OtelBatchSpanRecordProcessor and
OtelPeriodicExportingMetricReader, and a listener on 4318 sees a connection, so
all three signals are known to detect rather than assumed to.

* [autofix.ci] apply automated fixes

* [autofix.ci] apply automated fixes (attempt 2/3)

* chore: auto-bake note keys and regenerate backend locales/en.json [skip ci]

* test: tighten the inert assertions from review

Provider check is now identity against the API's own default, captured before
lfx is imported at all. Checking "not an SDK provider" passed anything that was
neither the default nor an SDK type, and a custom provider in that gap records
and exports while looking inert. Measured: unconfigured keeps
ProxyTracerProvider and _ProxyMeterProvider, configured replaces both.

Every OTLP port must now be bound before the test runs, not just one. Binding
4318 while 4317 was taken left the test reporting inertness it had not checked,
so a regression that connected to 4317 would have passed. The skip also moved
inside the try block, since skipping before it leaked the socket that did bind.

* test: exercise exported telemetry scopes

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Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Eric Hare <ericrhare@gmail.com>