ref(core): Remove deprecated Instrumenter option

[adinauer]

📜 Description

Removes the deprecated Instrumenter configuration and related tracing code for Java SDK 9:

• removes the Instrumenter enum and SentryOptions option
• removes instrumenter state from SpanContext
• removes instrumenter-specific ISpan.startChild overloads and filtering
• updates SDK integrations and OpenTelemetry adapters to use SpanOptions for explicit start timestamps

This complements #6243, which removes the deprecated OpenTelemetry implementations that originally required instrumenter selection.

💡 Motivation and Context

The current OpenTelemetry integration no longer relies on choosing between SENTRY and OTEL instrumenters. Keeping this deprecated option adds public API and conditional tracing paths without a supported use case. Java SDK 9 is the appropriate breaking-change boundary for removing it.

💚 How did you test it?

• ./gradlew spotlessApply apiDump
• ./gradlew ':sentry:test' ':sentry-android-core:testReleaseUnitTest' ':sentry-android-sqlite:testReleaseUnitTest' ':sentry-compose:testReleaseUnitTest' ':sentry-opentelemetry:sentry-opentelemetry-core:test' ':sentry-opentelemetry:sentry-opentelemetry-bootstrap:test' --info
  • 5,691 tests passed and 2 skipped

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the 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.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.
• Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec.

🔮 Next steps

None.

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.59.0 (1)	release

⚙️ sentry-android Build Distribution Settings

[adinauer]

These are marked internal on ISpan