Release Cleanup: Prevent release lane from running locally (#517)

* Initial plan

* chore: add CI-only guard to release lane

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Co-authored-by: mokagio <1218433+mokagio@users.noreply.github.com>

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---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: mokagio <1218433+mokagio@users.noreply.github.com>
Co-authored-by: Gio Lodi <gio@mokacoding.com>

Author: Copilot

fastlane/Fastfile

@@ -77,6 +77,8 @@ end
 # Release. For local diagnosis, invoke `validate`, `update_swift_package`,
 # `publish_to_s3`, or `publish_release_to_github` individually.
 lane :release do |options|
+  UI.user_error!('This lane must only run in CI.') unless ENV['CI']
+
   version = required_version!(options)
   token = github_token!(options)