Upgrade to Micrometer 2.0.0-M3

[wilkinsona]

No description provided.

[wilkinsona]

This is blocked due to the breaking API changes affecting other projects. The following modules are affected:

• HikariCP
• lettuce-core
• spring-batch-core
• spring-kafka
• stream-client (RabbitMQ)

spring-batch-core is the most problematic as Micrometer is integrated into AbstractJob. This means that we can only avoid the problem by removing Batch support entirely. For the others, we would only lose metrics integration.

[mhalbritter]

See #30014 for the ticket which handles the micrometer-binders module. As soon as a micrometer 2.0.0 with the binders module is published, we should refactor the imports.

It's as easy as replace every import io.micrometer.core.instrument.binder. with import io.micrometer.binder. for every import except MeterBinder.

The auto-configurations only need to support the new binders, as Spring Boot 3.0 drops support for the old binders, therefore we don't need to do all the auto-configuration changes we did for 2.7 in #30014

[mhalbritter]

main branch now builds against Micrometer 2.0.0-SNAPSHOT, which will be released as Micrometer 2.0.0-M3 on 2022-03-14.