Update helium-swift SDK to 4.5.2

[github-actions]

Automated update of helium-swift SDK dependency to version 4.5.2.

Changes:

• Updated Package.swift dependency version
• Updated podspec dependency version
• Bumped helium_flutter pubspec.yaml version (patch increment)
• Bumped helium_revenuecat pubspec.yaml version (patch increment)
• Updated heliumFlutterSdkVersion constant
• Added changelog entries to both packages

This PR was automatically created by the iOS SDK release workflow.

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Note

Low Risk
Version and native dependency pin updates only; no application logic or public API changes in the diff.

Overview
Release 3.3.5 bumps the iOS helium-swift native dependency from 4.4.8 to 4.5.2 in Package.swift and helium_flutter.podspec, and aligns package versions and release notes.

helium_flutter and helium_revenuecat are both bumped to 3.3.5 in pubspec.yaml, with matching 3.3.5 entries in each CHANGELOG.md. The reported SDK version in heliumFlutterSdkVersion is updated to 3.3.5. There are no Dart or plugin API changes in this diff—only dependency and version metadata.

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