Consider disabling usage of `SentryReactorThreadLocalAccessor` if OpenTelemetry is used

[adinauer]

Description

SentryReactorThreadLocalAccessor should not be necessary if OpenTelemetry is used for scope propagation through its Context instead of relying on our own ThreadLocal.

Also see #4806

We could skip using SentryReactorUtils in WebFlux if OpenTelemetry is being used, unless sentry.reactive.thread-local-accessor-enabled is set to true.

[linear]

JAVA-210