meta: enable library evolution in our podspec hybrid subspec

[armcknight]

When I tried updating CI use Xcode 16.4 I started getting these linter warnings that failed the build from podspec validation:

2025-07-02T19:12:48.8538080Z     - WARN  | [Sentry/Core,Sentry/HybridSDK] xcodebuild:  /Users/runner/work/sentry-cocoa/sentry-cocoa/Sources/Swift/Integrations/Performance/IO/Data+SentryTracing.swift:1:22: warning: using '@_implementationOnly' without enabling library evolution for 'Sentry' may lead to instability during execution

We do set BUILD_LIBRARY_FOR_DISTRIBUTION = YES in our xcconfigs, but those aren't used by cocoapods. Set it in the subspec that's having the issue.

[github-actions]

	Fails
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## Unreleased

- enable library evolution in our podspec hybrid subspec ([#5562](https://github.com/getsentry/sentry-cocoa/pull/5562))

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