fix(e2e): Pin json gem < 3.0 for RN < 0.72 iOS builds

[antonis]

📢 Type of change

• Bugfix

📜 Description

The RN 0.71.19 iOS E2E build (Setup Plain RN 0.71.19 App) started failing at bundle exec pod install:

[Codegen] Generating ./build/generated/ios/React-Codegen.podspec.json
[!] Invalid `Podfile` file: unknown keyword: quirks_mode.
 #  from .../0.71.19/RnDiffApp/ios/Podfile:30
 >    use_react_native!(

RN < 0.72 runs its iOS codegen while CocoaPods evaluates the Podfile (use_react_native!), and that codegen still passes quirks_mode: true to the json gem. The cloned rn-diff-purge Gemfile pins cocoapods and activesupport but not json, so a fresh bundle install floats to the latest json.

This change appends gem 'json', '< 3.0' to the app's Gemfile before bundle install, guarded to iOS + RN < 0.72. Newer RN (0.87.1) codegen dropped the quirks_mode usage and is unaffected — which is why only the 0.71.19 iOS job was red.

💡 Motivation and Context

• CI failure

💚 How did you test it?

• CI job passing

📝 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.
• Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec.
• 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(e2e): Pin json gem < 3.0 for RN < 0.72 iOS builds by antonis in #6678

• feat(ios): Expose enableMemoryIntrospection option by antonis in #6674
• feat(android): Add anrProfilingSampleRate option by antonis in #6673
• ci: Unpin Android E2E emulator build by antonis in #6672
• ref(ios): Remove deprecated private SDK API usage by philprime in #6647
• chore(deps): update Cocoa SDK to v9.27.0 by github-actions in #6670
• chore(deps): update Sentry Android Gradle Plugin to v6.21.0 by github-actions in #6671
• chore(deps): Bump fast-uri to ^3.1.6 to resolve security alerts by antonis in #6662
• chore(deps): Bump qs to ^6.16.0 to resolve security alerts by antonis in #6663
• chore(deps): Bump @xmldom/xmldom pins to patched versions to resolve security alerts by antonis in #6664
• docs: Revamp root and nested AGENTS.md by antonis in #6666

---

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

[github-actions]

iOS (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	3870.94 ms	1234.40 ms	-2636.54 ms
Size	5.15 MiB	6.88 MiB	1.73 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
ecf47a2+dirty	3835.20 ms	1222.43 ms	-2612.77 ms
3817909+dirty	1183.90 ms	1187.50 ms	3.60 ms
5ee78d6+dirty	3847.52 ms	1224.27 ms	-2623.25 ms
890d145+dirty	1223.59 ms	1231.37 ms	7.78 ms
e763471+dirty	3841.16 ms	1218.06 ms	-2623.09 ms
3d31fcf+dirty	3838.09 ms	1223.46 ms	-2614.63 ms
9210ae6+dirty	3815.93 ms	1214.14 ms	-2601.79 ms
26843eb+dirty	3861.60 ms	1238.77 ms	-2622.82 ms
7a89652+dirty	3861.46 ms	1229.61 ms	-2631.85 ms
9ad4522+dirty	3850.40 ms	1222.40 ms	-2628.00 ms

App size

Revision	Plain	With Sentry	Diff
ecf47a2+dirty	4.98 MiB	6.46 MiB	1.49 MiB
3817909+dirty	3.38 MiB	4.73 MiB	1.35 MiB
5ee78d6+dirty	5.15 MiB	6.69 MiB	1.53 MiB
890d145+dirty	3.38 MiB	4.77 MiB	1.38 MiB
e763471+dirty	4.98 MiB	6.51 MiB	1.53 MiB
3d31fcf+dirty	4.98 MiB	6.56 MiB	1.58 MiB
9210ae6+dirty	5.15 MiB	6.68 MiB	1.53 MiB
26843eb+dirty	4.98 MiB	6.53 MiB	1.55 MiB
7a89652+dirty	5.15 MiB	6.70 MiB	1.55 MiB
9ad4522+dirty	4.98 MiB	6.56 MiB	1.58 MiB

[github-actions]

Android (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	429.16 ms	460.60 ms	31.44 ms
Size	50.56 MiB	56.46 MiB	5.90 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
57e0069+dirty	413.82 ms	453.47 ms	39.65 ms
6acdf1d+dirty	513.58 ms	608.31 ms	94.72 ms
0bd8916+dirty	412.77 ms	451.31 ms	38.54 ms
7d6fd3a+dirty	403.02 ms	422.56 ms	19.54 ms
a2585ce+dirty	426.36 ms	483.26 ms	56.90 ms
a216cb9+dirty	458.66 ms	531.47 ms	72.81 ms
20fbd51+dirty	487.89 ms	535.60 ms	47.71 ms
88735e9+dirty	429.04 ms	484.17 ms	55.13 ms
eb93136+dirty	416.18 ms	467.32 ms	51.14 ms
0a9e622+dirty	420.73 ms	464.83 ms	44.10 ms

App size

Revision	Plain	With Sentry	Diff
57e0069+dirty	49.74 MiB	54.85 MiB	5.11 MiB
6acdf1d+dirty	49.74 MiB	55.09 MiB	5.34 MiB
0bd8916+dirty	48.30 MiB	53.57 MiB	5.26 MiB
7d6fd3a+dirty	43.75 MiB	48.14 MiB	4.39 MiB
a2585ce+dirty	49.74 MiB	55.36 MiB	5.61 MiB
a216cb9+dirty	49.74 MiB	55.08 MiB	5.34 MiB
20fbd51+dirty	49.74 MiB	54.81 MiB	5.07 MiB
88735e9+dirty	49.74 MiB	54.82 MiB	5.07 MiB
eb93136+dirty	48.30 MiB	53.58 MiB	5.28 MiB
0a9e622+dirty	49.74 MiB	55.09 MiB	5.34 MiB