fix(ios): Return NO from requiresMainQueueSetup

[antonis]

📢 Type of change

• Bugfix
• New feature
• Enhancement
• Refactoring

📜 Description

Return NO from +requiresMainQueueSetup in RNSentry.mm. The module's init only performs a trivial NSObject allocation (RNSentryTimeToDisplay), which has no main-thread requirement.

Note that methodQueue still returns dispatch_get_main_queue(), so all exported RCT methods continue to execute on the main thread as before.

💡 Motivation and Context

When requiresMainQueueSetup returns YES, React Native uses dispatch_sync(mainQueue, ...) to initialize the module during bridge setup. This unnecessary synchronization point can contribute to startup hangs if the main thread is blocked.

This was originally set to YES in 2017 when methodQueue was changed to return the main queue, but init never actually required main-thread execution.

Fixes #6201

💚 How did you test it?

This is a one-line change to a React Native module lifecycle constant. The sample app CI builds validate that the app starts correctly.

📝 Checklist

• I added tests to verify changes
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled
• I updated the docs if needed.
• I updated the wizard if needed.
• All tests passing
• No breaking changes

🔮 Next steps

[github-actions]

Semver Impact of This PR

⚪ None (no version bump detected)

📋 Changelog Preview

This is how your changes will appear in the changelog.
Entries from this PR are highlighted with a left border (blockquote style).

---

• fix(ios): Return NO from requiresMainQueueSetup by antonis in #6202

• feat(core): Expose pauseAppHangTracking and resumeAppHangTracking APIs by antonis in #6192

---

_{🤖 This preview updates automatically when you update the PR.}

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
Sentry RN	io.sentry.reactnative.sample	8.12.0 (89)	Release

⚙️ sentry-react-native Build Distribution Settings

[github-actions]

iOS (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	3835.69 ms	1209.92 ms	-2625.77 ms
Size	5.15 MiB	6.68 MiB	1.53 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
3817909+dirty	1183.90 ms	1187.50 ms	3.60 ms
44c8b3f+dirty	3823.85 ms	1207.66 ms	-2616.19 ms
b0d3373+dirty	3831.75 ms	1227.29 ms	-2604.46 ms
7d6fd3a+dirty	1223.29 ms	1229.57 ms	6.28 ms
6176a94+dirty	3836.50 ms	1217.64 ms	-2618.86 ms
5c1e987+dirty	1204.30 ms	1222.15 ms	17.85 ms
3d377b5+dirty	1218.48 ms	1219.51 ms	1.03 ms
7d8c8bd+dirty	3837.24 ms	1215.51 ms	-2621.73 ms
4966363+dirty	3854.04 ms	1231.55 ms	-2622.50 ms
5fe1c6c+dirty	1220.79 ms	1217.63 ms	-3.16 ms

App size

Revision	Plain	With Sentry	Diff
3817909+dirty	3.38 MiB	4.73 MiB	1.35 MiB
44c8b3f+dirty	5.15 MiB	6.66 MiB	1.51 MiB
b0d3373+dirty	5.15 MiB	6.68 MiB	1.53 MiB
7d6fd3a+dirty	3.38 MiB	4.77 MiB	1.39 MiB
6176a94+dirty	5.15 MiB	6.68 MiB	1.53 MiB
5c1e987+dirty	3.38 MiB	4.73 MiB	1.35 MiB
3d377b5+dirty	3.38 MiB	4.76 MiB	1.38 MiB
7d8c8bd+dirty	5.15 MiB	6.68 MiB	1.53 MiB
4966363+dirty	5.15 MiB	6.68 MiB	1.53 MiB
5fe1c6c+dirty	3.38 MiB	4.77 MiB	1.39 MiB

[github-actions]

iOS (new) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	3857.24 ms	1228.83 ms	-2628.41 ms
Size	5.15 MiB	6.68 MiB	1.53 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
3817909+dirty	1210.76 ms	1215.64 ms	4.89 ms
44c8b3f+dirty	3849.24 ms	1209.94 ms	-2639.31 ms
b0d3373+dirty	3842.49 ms	1218.49 ms	-2624.00 ms
7d6fd3a+dirty	1210.89 ms	1217.63 ms	6.74 ms
6176a94+dirty	3854.15 ms	1221.77 ms	-2632.38 ms
5c1e987+dirty	1208.43 ms	1220.72 ms	12.29 ms
3d377b5+dirty	1201.55 ms	1201.80 ms	0.25 ms
7d8c8bd+dirty	3847.98 ms	1230.77 ms	-2617.21 ms
4966363+dirty	3863.07 ms	1227.19 ms	-2635.88 ms
5fe1c6c+dirty	1201.36 ms	1209.15 ms	7.78 ms

App size

Revision	Plain	With Sentry	Diff
3817909+dirty	3.38 MiB	4.73 MiB	1.35 MiB
44c8b3f+dirty	5.15 MiB	6.66 MiB	1.51 MiB
b0d3373+dirty	5.15 MiB	6.68 MiB	1.53 MiB
7d6fd3a+dirty	3.38 MiB	4.77 MiB	1.39 MiB
6176a94+dirty	5.15 MiB	6.68 MiB	1.53 MiB
5c1e987+dirty	3.38 MiB	4.73 MiB	1.35 MiB
3d377b5+dirty	3.38 MiB	4.76 MiB	1.38 MiB
7d8c8bd+dirty	5.15 MiB	6.68 MiB	1.53 MiB
4966363+dirty	5.15 MiB	6.68 MiB	1.53 MiB
5fe1c6c+dirty	3.38 MiB	4.77 MiB	1.39 MiB