prepare 9.2.0 release (#261)

## [9.2.0] - 2024-03-20
### Added:
- iOS: Stores and uses e-tag header between SDK initializations for
improved initialization

### Changed:
- iOS: Calling identify() with a context that is identical to the SDK's
current context is now more efficient, and no longer results in
re-establishing a connection.

### Fixed:
- iOS: Prevent null value changes to observe listeners
- iOS: Fixed issue where flag change listeners were not being triggered
when identify() was called.

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Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: Ember Stevens <[email protected]>
Co-authored-by: Ember Stevens <[email protected]>
Co-authored-by: Yusinto Ngadiman <[email protected]>
Co-authored-by: Yusinto Ngadiman <[email protected]>
Co-authored-by: LaunchDarklyReleaseBot <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: tanderson-ld <[email protected]>
Co-authored-by: Louis Chan <[email protected]>
Co-authored-by: Louis Chan <[email protected]>

Author: 7 people