docs: update CONTRIBUTING paths for the monorepo layout

[melbinjp]

📢 Type of change

• Bugfix
• New feature
• Enhancement
• Refactoring

📜 Description

Three CONTRIBUTING.md paths predate the monorepo move and no longer exist at the root:

line	says	now at
158	sample/ios/Podfile	samples/react-native/ios/Podfile
189	sample/android/build.gradle	samples/react-native/android/build.gradle
199	android/build.gradle	packages/core/android/build.gradle

Path corrections only.

💡 Motivation and Context

The repository moved in ddcabffc ("misc: Move to monorepo structure and Yarn V3 (#4057)"); sample/ios/Podfile went earlier in 2d3b9f2b. The root has neither android/ nor sample/, so the local-SDK sections point at nothing.

Each replacement is the file the instruction means:

• packages/core/android/build.gradle:186 is api "io.sentry:sentry-android:$sentryAndroidVersion"
• samples/react-native/android/build.gradle:24 opens repositories { maven {
• samples/react-native/ios/Podfile:44 is pod 'AppTurboModules', :path => "./../tm"

💚 How did you test it?

Resolved each path against the current tree: three absent, three present with the referenced content. No code changed.

📝 Checklist

• I added tests to verify changes. (documentation only)
• No new PII added.
• I updated the docs if needed.
• I updated the wizard if needed. (n/a)
• All tests passing. (no code changed)
• No breaking changes.

AI use

Your CONTRIBUTING.md asks that changes be reviewed and tested by a human first, and says agent-generated "fix" PRs will be closed. Straight answer: a documentation checker found these paths. Each was confirmed against git log for the commit that moved it, each replacement opened and checked, and the change read before submitting. If you would rather not take it, close it.

[antonis]

LGTM. Thank you for catching this and contributing the fix @melbinjp 🙇