Version 1.34.1/0.55b1

[github-actions[bot]]

This is a patch release on the previous 1.34.0/0.55b0 release, fixing the issue(s) below.

• opentelemetry-sdk: Fix invalid type: ignore that causes mypy to ignore the whole file (#4618)
• Add span_exporter property back to BatchSpanProcessor class (#4621)

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This discussion was created from the release Version 1.34.1/0.55b1.