feat: add support for converting optional chaining to regular chaining

[feywind]

Some samples in testing needed optional chaining support, and this is not supported by the versions of gts (and all Node versions) that we use.

[snippet-bot]

Here is the summary of changes.

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• packages/typeless-sample-bot/snapshots/index.js:123, tag pubsub_subscribe_avro_records

You are about to delete 1 region tag.

• packages/typeless-sample-bot/snapshots/index.js:123, tag pubsub_subscribe_avro_records

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