ci: configure RN to release as a prerelease version

[joker23]

This is to prep a major version update of RN

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Note

Low Risk
CI and release-please config only; no runtime SDK code changes, with explicit revert path at GA.

Overview
Configures React Native SDK automated releases for the upcoming v11 major so versions ship as beta prereleases instead of updating npm latest (still on v10 until GA).

release-please-config.json now sets prerelease: true and prerelease-type: beta for packages/sdk/react-native, so release-please bumps with beta suffixes. The release-react-native workflow passes prerelease: true into full-release, which publishes without moving the latest dist-tag. Comments note removing both once v11 is GA.

^{Reviewed by Cursor Bugbot for commit bfa69d1. Bugbot is set up for automated code reviews on this repo. Configure here.}

[github-actions]

@launchdarkly/js-sdk-common size report
This is the brotli compressed size of the ESM build.
Compressed size: 26360 bytes
Compressed size limit: 29000
Uncompressed size: 129188 bytes

[github-actions]

@launchdarkly/js-client-sdk-common size report
This is the brotli compressed size of the ESM build.
Compressed size: 39108 bytes
Compressed size limit: 39300
Uncompressed size: 213642 bytes

[github-actions]

@launchdarkly/browser size report
This is the brotli compressed size of the ESM build.
Compressed size: 179796 bytes
Compressed size limit: 200000
Uncompressed size: 831704 bytes

[github-actions]

@launchdarkly/js-client-sdk size report
This is the brotli compressed size of the ESM build.
Compressed size: 32077 bytes
Compressed size limit: 34000
Uncompressed size: 114525 bytes

[joker23]

@cursor review

[cursor]

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit bfa69d1. Configure here.}