fix(tests): don't include trace context in symbolicator snapshots

[shellmayr]

• Changes necessary due to a change in relay
• Example for failing tests on some PRs
• Snapshots generated using SENTRY_SNAPSHOTS_WRITEBACK=new pytest tests/symbolicator/ locally with devservices relay and symbolicator ended up being volatile (unique IDs)
• Use approach to exclude the trace context from the snapshot as has been done with the reprocessing context

[cursor]

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