[ReactNativation] [ExpoRouter] Discard invalid navigation and interaction root spans using event processor instead `sampled=false`

[krystofwoldrich]

Description

This will resolved confusing dropped transactions and spans due to sampling, although sample_rate=1.

Current use of sampled=false.

https://github.com/getsentry/sentry-react-native/blob/18ce5e87b6e981e23ef9493207fb152d9c6aa8e7/packages/core/src/js/tracing/onSpanEndUtils.ts#L86 https://github.com/getsentry/sentry-react-native/blob/18ce5e87b6e981e23ef9493207fb152d9c6aa8e7/packages/core/src/js/tracing/onSpanEndUtils.ts#L111 https://github.com/getsentry/sentry-react-native/blob/18ce5e87b6e981e23ef9493207fb152d9c6aa8e7/packages/core/src/js/tracing/reactnativenavigation.ts#L214 https://github.com/getsentry/sentry-react-native/blob/f2d10b7bd12e10b57209f3a1651d1f37b33e08b1/packages/core/src/js/tracing/reactnavigation.ts#L333