Upgrade to Micrometer 1.9.0-M4

[mhalbritter]

Micrometer 1.9.0-M4 duplicates the binders in a separate module named
micrometer-binders, and marks the binders in the core module as
deprecated. This change is done to ease the migration to 2.0.0, where the binders in the core modules will be dropped.

Spring Boot should build against Micrometer 1.9.0-M4 and use the binders in the micrometer-binders module. However, user-contributed beans should still work even if they come from the micrometer-core module.

We should note in the release notes that with Spring Boot 3.0, which will use Micrometer 2.0, the support for the old binders in micrometer-core will be dropped.

[mhalbritter]

The 2.7.x branch now builds against micrometer 1.9.0-snapshot. The main branch still builds against 2.0.0-M1, and I applied none of the changes from 2.7.x to main. We now wait until Micrometer 2.0.0 has the new micrometer-binders module, too.

[mhalbritter]

We will track the Micrometer 2.0.0 changes in #29753