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## 1.70.3

**`(fix):`** Unknown JSON keys that match a declared field's wire name case-insensitively (e.g. `VALUE` next to a
declared `value`) are no longer kept in `ExtraProperties` when decoding, so they are not re-emitted
after the declared field on encode. Case-insensitive, last-wins decoders such as Go's `encoding/json`
would otherwise read the re-emitted key instead of the declared field. `MarshalJSONWithExtraProperties`
now also rejects extra properties that collide case-insensitively with a declared key. Unknown keys
that don't collide (e.g. `brand_new_field`) are still preserved and round-tripped.