Fix flaky core plugin live test

[pvaneck]

One test in the tracing plugin frequently fails on windows during nightly live test runs. This test was adjusted to make it more reliable.

[Copilot]

Pull request overview

Stabilizes a flaky live test in the OpenTelemetry tracing plugin by signaling completion of event consumption with a threading.Event instead of relying on a fixed 3-second join, polling for span export, and shifting the starting position back 30 seconds to tolerate clock skew.

Changes:

• Use a threading.Event set inside on_event_batch and wait up to 60s for the batch.
• Poll up to 10s for finished spans before asserting the expected count.
• Subtract 30s from datetime.now() to mitigate client/service clock skew.

Show a summary per file

File	Description
sdk/core/azure-core-tracing-opentelemetry/tests/test_eventhubs_live.py	Replaces fixed-timeout join with event signaling, polls for spans, and offsets the receive starting timestamp.

Copilot's findings

• Files reviewed: 1/1 changed files
• Comments generated: 0