[Fix]CallKitService storage access

[ipavlidakis]

🔗 Issue Links

https://getstream.zendesk.com/agent/tickets/56365

📝 Summary

When performing the EndCall action provider in CallKit, there is an access issue occurring, because at the same time we receive and process a callEnded event from the Stream backend.

🛠 Implementation

We now ensure that access to the internal callEntry storage is thread-safe.

☑️ Contributor Checklist

• [x] I have signed the Stream CLA (required)
• [x] This change follows zero ⚠️ policy (required)
• [x] This change should receive manual QA
• [x] Changelog is updated with client-facing changes
• [ ] New code is covered by unit tests
• [ ] Comparison screenshots added for visual changes
• [ ] Affected documentation updated (Docusaurus, tutorial, CMS)

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
StreamVideo	7.97 MB	7.97 MB	0 KB	🟢
StreamVideoSwiftUI	2.18 MB	2.18 MB	0 KB	🟢
StreamVideoUIKit	2.31 MB	2.31 MB	0 KB	🟢
StreamWebRTC	8.69 MB	8.69 MB	0 KB	🟢

[sonarcloud[bot]]

Quality Gate passed

Issues
111 New issues
0 Accepted issues

Measures
0 Security Hotspots
79.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud