Log spam due to micrometer instrumentation #2913

Describe the bug

Reported in the discussion forums:

Upgrading from 1.34.1 to 1.35.0 of the Java agent, in a Spring Boot application.
During startup, this is logged hundreds of times on multiple threads:

2022-12-06 14:40:47,793 [main] INFO  co.elastic.apm.agent.micrometer.MicrometerMetricsReporter - Not re-registering MeterRegistry as it is already registered from another compound meter registry: io.micrometer.core.instrument.simple.SimpleMeterRegistry@5c2f5dc
2022-12-06 14:40:49,984 [main] INFO  co.elastic.apm.agent.micrometer.MicrometerMetricsReporter - Not re-registering MeterRegistry as it is already registered from another compound meter registry: io.micrometer.core.instrument.simple.SimpleMeterRegistry@5c2f5dc
2022-12-06 14:40:51,407 [Service Thread] INFO  co.elastic.apm.agent.micrometer.MicrometerMetricsReporter - Not re-registering MeterRegistry as it is already registered from another compound meter registry: io.micrometer.core.instrument.simple.SimpleMeterRegistry@5c2f5dc
2022-12-06 14:40:56,710 [lettuce-nioEventLoop-4-1] INFO  co.elastic.apm.agent.micrometer.MicrometerMetricsReporter - Not re-registering MeterRegistry as it is already registered from another compound meter registry: io.micrometer.core.instrument.simple.SimpleMeterRegistry@5c2f5dc
2022-12-06 14:40:57,144 [lettuce-nioEventLoop-4-2] INFO  co.elastic.apm.agent.micrometer.MicrometerMetricsReporter - Not re-registering MeterRegistry as it is already registered from another compound meter registry: io.micrometer.core.instrument.simple.SimpleMeterRegistry@5c2f5dc
2022-12-06 14:40:59,294 [lettuce-nioEventLoop-4-3] INFO  co.elastic.apm.agent.micrometer.MicrometerMetricsReporter - Not re-registering MeterRegistry as it is already registered from another compound meter registry: io.micrometer.core.instrument.simple.SimpleMeterRegistry@5c2f5dc

And then again on a request:

2022-12-06 14:48:25,876 [Service Thread] INFO  co.elastic.apm.agent.micrometer.MicrometerMetricsReporter - Not re-registering MeterRegistry as it is already registered from another compound meter registry: io.micrometer.core.instrument.simple.SimpleMeterRegistry@5c2f5dc
2022-12-06 14:48:26,333 [XNIO-1 task-1] INFO  co.elastic.apm.agent.micrometer.MicrometerMetricsReporter - Not re-registering MeterRegistry as it is already registered from another compound meter registry: io.micrometer.core.instrument.simple.SimpleMeterRegistry@5c2f5dc
2022-12-06 14:48:26,654 [XNIO-1 task-1] INFO  co.elastic.apm.agent.micrometer.MicrometerMetricsReporter - Not re-registering MeterRegistry as it is already registered from another compound meter registry: io.micrometer.core.instrument.simple.SimpleMeterRegistry@5c2f5dc
2022-12-06 14:48:26,870 [XNIO-1 task-1] INFO  co.elastic.apm.agent.micrometer.

This has most likely been introduced via #2801. We should revist the log changes there and either remove them or adjust the logging levels.